diff --git a/CHANGELOG.md b/CHANGELOG.md
index 51d38ade7..14ee3759e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,14 @@
 Changelog
 =========
 
+## TBD
+
+### Enhancements
+
+* Capture basic report diagnostics in the file path in case of crash report
+  content corruption
+  [#327](https://github.com/bugsnag/bugsnag-cocoa/pull/327)
+
 ## 5.17.3 (2018-12-19)
 
 ### Bug Fixes
diff --git a/OSX/Bugsnag.xcodeproj/project.pbxproj b/OSX/Bugsnag.xcodeproj/project.pbxproj
index eb63a4c0f..875a33720 100644
--- a/OSX/Bugsnag.xcodeproj/project.pbxproj
+++ b/OSX/Bugsnag.xcodeproj/project.pbxproj
@@ -7,6 +7,7 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		8A12006C221C50F40008C9C3 /* BSGFilepathTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 8A12006B221C50F40008C9C3 /* BSGFilepathTests.m */; };
 		8A2C8FAC1C6BC1F700846019 /* Bugsnag.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 8A2C8FA11C6BC1F700846019 /* Bugsnag.framework */; };
 		8A2C8FCD1C6BC2C800846019 /* Bugsnag.h in Headers */ = {isa = PBXBuildFile; fileRef = 8A2C8FBB1C6BC2C800846019 /* Bugsnag.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		8A2C8FCE1C6BC2C800846019 /* Bugsnag.m in Sources */ = {isa = PBXBuildFile; fileRef = 8A2C8FBC1C6BC2C800846019 /* Bugsnag.m */; };
@@ -188,6 +189,7 @@
 /* End PBXContainerItemProxy section */
 
 /* Begin PBXFileReference section */
+		8A12006B221C50F40008C9C3 /* BSGFilepathTests.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = BSGFilepathTests.m; sourceTree = "<group>"; };
 		8A2C8FA11C6BC1F700846019 /* Bugsnag.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = Bugsnag.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		8A2C8FA61C6BC1F700846019 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
 		8A2C8FAB1C6BC1F700846019 /* Tests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = Tests.xctest; sourceTree = BUILT_PRODUCTS_DIR; };
@@ -469,6 +471,7 @@
 		8A2C8FAF1C6BC1F700846019 /* Tests */ = {
 			isa = PBXGroup;
 			children = (
+				8A12006B221C50F40008C9C3 /* BSGFilepathTests.m */,
 				E7CE78861FD94E40001D07E0 /* KSCrash */,
 				E791482D1FD82B0C003EFEBF /* BugsnagSessionTest.m */,
 				E791482B1FD82B0C003EFEBF /* BugsnagSessionTrackerTest.m */,
@@ -933,6 +936,7 @@
 				8ACF0F752018136200173809 /* BugsnagCrashReportTests.m in Sources */,
 				E7CE78CC1FD94E77001D07E0 /* KSSystemInfo_Tests.m in Sources */,
 				E7CE78C91FD94E77001D07E0 /* KSSignalInfo_Tests.m in Sources */,
+				8A12006C221C50F40008C9C3 /* BSGFilepathTests.m in Sources */,
 				E7CE78C61FD94E77001D07E0 /* KSMach_Tests.m in Sources */,
 				E7CE78D61FD94E9E001D07E0 /* FileBasedTestCase.m in Sources */,
 				E7CE78D51FD94E93001D07E0 /* XCTestCase+KSCrash.m in Sources */,
diff --git a/Source/BugsnagApiClient.h b/Source/BugsnagApiClient.h
index 1c37a3054..d1cca8eab 100644
--- a/Source/BugsnagApiClient.h
+++ b/Source/BugsnagApiClient.h
@@ -7,7 +7,7 @@
 
 @class BugsnagConfiguration;
 
-typedef void (^RequestCompletion)(id data, BOOL success, NSError *error);
+typedef void (^RequestCompletion)(NSUInteger reportCount, BOOL success, NSError *error);
 
 @interface BugsnagApiClient : NSObject
 
@@ -21,11 +21,11 @@ typedef void (^RequestCompletion)(id data, BOOL success, NSError *error);
 
 - (NSOperation *)deliveryOperation;
 
-- (void)sendData:(id)data
-     withPayload:(NSDictionary *)payload
-           toURL:(NSURL *)url
-         headers:(NSDictionary *)headers
-    onCompletion:(RequestCompletion)onCompletion;
+- (void)sendItems:(NSUInteger)count
+      withPayload:(NSDictionary *)payload
+            toURL:(NSURL *)url
+          headers:(NSDictionary *)headers
+     onCompletion:(RequestCompletion)onCompletion;
 
 @property(readonly) NSOperationQueue *sendQueue;
 @property(readonly) BugsnagConfiguration *config;
diff --git a/Source/BugsnagApiClient.m b/Source/BugsnagApiClient.m
index 8550286c2..2463844f4 100644
--- a/Source/BugsnagApiClient.m
+++ b/Source/BugsnagApiClient.m
@@ -49,11 +49,11 @@ - (NSOperation *)deliveryOperation {
 #pragma mark - Delivery
 
 
-- (void)sendData:(id)data
-     withPayload:(NSDictionary *)payload
-           toURL:(NSURL *)url
-         headers:(NSDictionary *)headers
-    onCompletion:(RequestCompletion)onCompletion {
+- (void)sendItems:(NSUInteger)count
+      withPayload:(NSDictionary *)payload
+            toURL:(NSURL *)url
+          headers:(NSDictionary *)headers
+     onCompletion:(RequestCompletion)onCompletion {
 
     @try {
         NSError *error = nil;
@@ -64,7 +64,7 @@ - (void)sendData:(id)data
 
         if (jsonData == nil) {
             if (onCompletion) {
-                onCompletion(data, NO, error);
+                onCompletion(0, NO, error);
             }
             return;
         }
@@ -79,7 +79,7 @@ - (void)sendData:(id)data
                                 NSURLResponse *_Nullable response,
                                 NSError *_Nullable requestErr) {
                             if (onCompletion) {
-                                onCompletion(data, requestErr == nil, requestErr);
+                                onCompletion(count, requestErr == nil, requestErr);
                             }
                         }];
             [task resume];
@@ -92,13 +92,13 @@ - (void)sendData:(id)data
                                   returningResponse:&response
                                               error:&error];
             if (onCompletion) {
-                onCompletion(data, error == nil, error);
+                onCompletion(count, error == nil, error);
             }
 #pragma clang diagnostic pop
         }
     } @catch (NSException *exception) {
         if (onCompletion) {
-            onCompletion(data, NO,
+            onCompletion(count, NO,
                     [NSError            errorWithDomain:exception.reason
                                         code:420
                                     userInfo:@{BSGKeyException: exception}]);
diff --git a/Source/BugsnagCrashReport.h b/Source/BugsnagCrashReport.h
index 6d82b7a55..027a9fde1 100644
--- a/Source/BugsnagCrashReport.h
+++ b/Source/BugsnagCrashReport.h
@@ -39,6 +39,18 @@ NSString *_Nonnull BSGFormatSeverity(BSGSeverity severity);
 
 @interface BugsnagCrashReport : NSObject
 
+/**
+ *  Create a new crash report from a JSON crash report generated by
+ * BugsnagCrashSentry
+ *
+ *  @param report a BugsnagCrashSentry JSON report
+ *  @param metadata additional report info encoded as a string
+ *
+ *  @return a Bugsnag crash report
+ */
+- (instancetype _Nonnull)initWithKSReport:(NSDictionary *_Nonnull)report
+                             fileMetadata:(NSString *_Nonnull)metadata;
+
 /**
  *  Create a new crash report from a JSON crash report generated by
  * BugsnagCrashSentry
@@ -193,6 +205,10 @@ __deprecated_msg("Use toJson: instead.");
  */
 @property(readwrite, copy, nullable) NSDictionary *appState;
 
+/**
+ * If YES, a complete report was not able to be obtained at generation time
+ */
+@property (readonly, nonatomic, getter=isIncomplete) BOOL incomplete;
 
 /**
  * Returns the enhanced error message for the thread, or nil if none exists.
diff --git a/Source/BugsnagCrashReport.m b/Source/BugsnagCrashReport.m
index 00eb36769..87c9aa5d7 100644
--- a/Source/BugsnagCrashReport.m
+++ b/Source/BugsnagCrashReport.m
@@ -70,7 +70,8 @@
 }
 
 NSString *_Nonnull BSGParseErrorClass(NSDictionary *error,
-                                      NSString *errorType) {
+                                      NSString *errorType,
+                                      NSString *fallbackValue) {
     NSString *errorClass;
 
     if ([errorType isEqualToString:BSGKeyCppException]) {
@@ -86,7 +87,7 @@
     }
 
     if (!errorClass) { // use a default value
-        errorClass = @"Exception";
+        errorClass = fallbackValue.length > 0 ? fallbackValue : @"Exception";
     }
     return errorClass;
 }
@@ -184,6 +185,13 @@ + (instancetype)errorDataFromThreads:(NSArray *)threads;
 - (instancetype)initWithClass:(NSString *_Nonnull)errorClass message:(NSString *_Nonnull)errorMessage NS_DESIGNATED_INITIALIZER;
 @end
 
+@interface FallbackReportData : NSObject
+@property (nonatomic, strong) NSString *errorClass;
+@property (nonatomic, getter=isUnhandled) BOOL unhandled;
+@property (nonatomic) BSGSeverity severity;
+- (instancetype)initWithMetadata:(NSString *)metadata;
+@end
+
 @interface BugsnagCrashReport ()
 
 /**
@@ -212,25 +220,33 @@ @interface BugsnagCrashReport ()
 @property(nonatomic, readwrite, copy, nullable) NSDictionary *customException;
 @property(nonatomic) BugsnagSession *session;
 
+@property (nonatomic, readwrite, getter=isIncomplete) BOOL incomplete;
 @end
 
 @implementation BugsnagCrashReport
 
 - (instancetype)initWithKSReport:(NSDictionary *)report {
+    return [self initWithKSReport:report fileMetadata:@""];
+}
+
+- (instancetype)initWithKSReport:(NSDictionary *)report
+                    fileMetadata:(NSString *)metadata {
     if (self = [super init]) {
+        FallbackReportData *fallback = [[FallbackReportData alloc] initWithMetadata:metadata];
         _notifyReleaseStages =
             [report valueForKeyPath:@"user.config.notifyReleaseStages"];
         _releaseStage = BSGParseReleaseStage(report);
 
         _error = [report valueForKeyPath:@"crash.error"];
+        _incomplete = report.count == 0;
         _errorType = _error[BSGKeyType];
         _threads = [report valueForKeyPath:@"crash.threads"];
         RegisterErrorData *data = [RegisterErrorData errorDataFromThreads:_threads];
         if (data) {
-            _errorClass = data.errorClass;
+            _errorClass = data.errorClass ?: fallback.errorClass;
             _errorMessage = data.errorMessage;
         } else {
-            _errorClass = BSGParseErrorClass(_error, _errorType);
+            _errorClass = BSGParseErrorClass(_error, _errorType, fallback.errorClass);
             _errorMessage = BSGParseErrorMessage(report, _error, _errorType);
         }
         _binaryImages = report[@"binary_images"];
@@ -259,7 +275,7 @@ - (instancetype)initWithKSReport:(NSDictionary *)report {
             // only makes sense to use serialised value for handled exceptions
             _depth = [[report valueForKeyPath:@"user.state.crash.depth"]
                     unsignedIntegerValue];
-        } else { // the event was unhandled.
+        } else if (_errorType != nil) { // the event was unhandled.
             BOOL isSignal = [BSGKeySignal isEqualToString:_errorType];
             SeverityReasonType severityReason =
                 isSignal ? Signal : UnhandledException;
@@ -268,6 +284,11 @@ - (instancetype)initWithKSReport:(NSDictionary *)report {
                                       severity:BSGSeverityError
                                      attrValue:_errorClass];
             _depth = 0;
+        } else { // Incomplete report
+            SeverityReasonType severityReason = [fallback isUnhandled] ? UnhandledException : HandledError;
+            _handledState = [BugsnagHandledState handledStateWithSeverityReason:severityReason
+                                                                       severity:fallback.severity
+                                                                      attrValue:nil];
         }
         _severity = _handledState.currentSeverity;
 
@@ -478,7 +499,11 @@ - (NSDictionary *)toJson {
     BSGDictSetSafeObject(event, BSGFormatSeverity(self.severity), BSGKeySeverity);
     BSGDictSetSafeObject(event, [self breadcrumbs], BSGKeyBreadcrumbs);
     BSGDictSetSafeObject(event, metaData, BSGKeyMetaData);
-    
+
+    if ([self isIncomplete]) {
+        BSGDictSetSafeObject(event, @YES, BSGKeyIncomplete);
+    }
+
     NSDictionary *device = [self.device bsg_mergedInto:self.deviceState];
     BSGDictSetSafeObject(event, device, BSGKeyDevice);
     
@@ -620,6 +645,42 @@ - (NSString *_Nullable)enhancedErrorMessageForThread:(NSDictionary *_Nullable)th
 
 @end
 
+@implementation FallbackReportData
+
+- (instancetype)initWithMetadata:(NSString *)metadata {
+    if (self = [super init]) {
+        NSString *separator = @"-";
+        NSString *location = metadata;
+        NSRange range = [location rangeOfString:separator options:NSBackwardsSearch];
+        if (range.location != NSNotFound) {
+            _errorClass = [location substringFromIndex:range.location + 1];
+            location = [location substringToIndex:range.location];
+        }
+        range = [location rangeOfString:separator options:NSBackwardsSearch];
+        if (range.location != NSNotFound) {
+            NSString *value = [location substringFromIndex:range.location + 1];
+            _unhandled = ![value isEqualToString:@"h"];
+            location = [location substringToIndex:range.location + 1];
+        } else {
+            _unhandled = YES;
+        }
+        range = [location rangeOfString:separator options:NSBackwardsSearch];
+        if (range.location != NSNotFound) {
+            NSString *value = [location substringFromIndex:range.location];
+            if ([value isEqualToString:@"w"]) {
+                _severity = BSGSeverityWarning;
+            } else if ([value isEqualToString:@"i"]) {
+                _severity = BSGSeverityInfo;
+            } else {
+                _severity = BSGSeverityError;
+            }
+        }
+    }
+    return self;
+}
+
+@end
+
 @implementation RegisterErrorData
 + (instancetype)errorDataFromThreads:(NSArray *)threads {
     for (NSDictionary *thread in threads) {
diff --git a/Source/BugsnagErrorReportApiClient.m b/Source/BugsnagErrorReportApiClient.m
index 0bf3b80b8..18b2d1cef 100644
--- a/Source/BugsnagErrorReportApiClient.m
+++ b/Source/BugsnagErrorReportApiClient.m
@@ -30,11 +30,11 @@ - (void)main {
     @autoreleasepool {
         @try {
             [[BSG_KSCrash sharedInstance]
-                    sendAllReportsWithCompletion:^(NSArray *filteredReports,
+                    sendAllReportsWithCompletion:^(NSUInteger sentReportCount,
                             BOOL completed, NSError *error) {
                         if (error) {
                             bsg_log_warn(@"Failed to send reports: %@", error);
-                        } else if (filteredReports.count > 0) {
+                        } else if (sentReportCount > 0) {
                             bsg_log_info(@"Reports sent.");
                         }
                     }];
diff --git a/Source/BugsnagFileStore.h b/Source/BugsnagFileStore.h
index 48a10510f..fad1e36aa 100644
--- a/Source/BugsnagFileStore.h
+++ b/Source/BugsnagFileStore.h
@@ -40,6 +40,12 @@
  */
 - (NSArray *)allFiles;
 
+/** Get a list of all files by filename.
+ *
+ * @return A collection of file contents indexed by filename.
+ */
+- (NSDictionary <NSString *, NSDictionary *> *)allFilesByName;
+
 /** Delete a file.
  *
  * @param fileId The file ID.
diff --git a/Source/BugsnagFileStore.m b/Source/BugsnagFileStore.m
index 5fadd7a0e..1eee97744 100644
--- a/Source/BugsnagFileStore.m
+++ b/Source/BugsnagFileStore.m
@@ -128,13 +128,17 @@ - (NSUInteger)fileCount {
 }
 
 - (NSArray *)allFiles {
+    return [[self allFilesByName] allValues];
+}
+
+- (NSDictionary <NSString *, NSDictionary *> *)allFilesByName {
     NSArray *fileIds = [self fileIds];
-    NSMutableArray *files =
-            [NSMutableArray arrayWithCapacity:[fileIds count]];
+    NSMutableDictionary *files =
+    [NSMutableDictionary dictionaryWithCapacity:[fileIds count]];
     for (NSString *fileId in fileIds) {
         NSDictionary *fileContents = [self fileWithId:fileId];
         if (fileContents != nil) {
-            [files addObject:fileContents];
+            [files setObject:fileContents forKey:fileId];
         }
     }
 
diff --git a/Source/BugsnagKeys.h b/Source/BugsnagKeys.h
index 54a89693f..aabd15608 100644
--- a/Source/BugsnagKeys.h
+++ b/Source/BugsnagKeys.h
@@ -19,6 +19,7 @@ static NSString *const BSGKeyName = @"name";
 static NSString *const BSGKeyTimestamp = @"timestamp";
 static NSString *const BSGKeyType = @"type";
 static NSString *const BSGKeyMetaData = @"metaData";
+static NSString *const BSGKeyIncomplete = @"incomplete";
 static NSString *const BSGKeyId = @"id";
 static NSString *const BSGKeyUser = @"user";
 static NSString *const BSGKeyEmail = @"email";
diff --git a/Source/BugsnagSessionTrackingApiClient.m b/Source/BugsnagSessionTrackingApiClient.m
index b140ecb7d..e63719e7e 100644
--- a/Source/BugsnagSessionTrackingApiClient.m
+++ b/Source/BugsnagSessionTrackingApiClient.m
@@ -47,11 +47,11 @@ - (void)deliverSessionsInStore:(BugsnagSessionFileStore *)store {
                                           @"Bugsnag-API-Key": apiKey,
                                           @"Bugsnag-Sent-At": [BSG_RFC3339DateTool stringFromDate:[NSDate new]]
                                           };
-            [self sendData:payload
-               withPayload:[payload toJson]
-                     toURL:sessionURL
-                   headers:HTTPHeaders
-              onCompletion:^(id data, BOOL success, NSError *error) {
+            [self sendItems:sessions.count
+                withPayload:[payload toJson]
+                      toURL:sessionURL
+                    headers:HTTPHeaders
+               onCompletion:^(NSUInteger sentCount, BOOL success, NSError *error) {
                   if (success && error == nil) {
                       bsg_log_info(@"Sent %lu sessions to Bugsnag", (unsigned long) sessionCount);
 
diff --git a/Source/BugsnagSink.m b/Source/BugsnagSink.m
index 0fc2517a1..f81920713 100644
--- a/Source/BugsnagSink.m
+++ b/Source/BugsnagSink.m
@@ -56,15 +56,18 @@ - (instancetype)initWithApiClient:(BugsnagErrorReportApiClient *)apiClient {
 // - the report-specific `notifyReleaseStages` property is unset and the global
 // `notifyReleaseStages` property
 //   and it contains the current stage
-- (void)filterReports:(NSArray *)reports
+- (void)filterReports:(NSDictionary <NSString *, NSDictionary *> *)reports
          onCompletion:(BSG_KSCrashReportFilterCompletion)onCompletion {
     NSMutableArray *bugsnagReports = [NSMutableArray new];
     BugsnagConfiguration *configuration = [Bugsnag configuration];
     
-    for (NSDictionary *report in reports) {
-        BugsnagCrashReport *bugsnagReport = [[BugsnagCrashReport alloc] initWithKSReport:report];
-        BOOL incompleteReport = (![@"standard" isEqualToString:[report valueForKeyPath:@"report.type"]] ||
-                                 [[report objectForKey:@"incomplete"] boolValue]);
+    for (NSString *fileKey in reports) {
+        NSDictionary *report = reports[fileKey];
+        BugsnagCrashReport *bugsnagReport = [[BugsnagCrashReport alloc] initWithKSReport:report
+                                                                            fileMetadata:fileKey];
+        BOOL incompleteReport = ([bugsnagReport isIncomplete]
+                                 || ![@"standard" isEqualToString:[report valueForKeyPath:@"report.type"]]
+                                 || [[report objectForKey:@"incomplete"] boolValue]);
         
         if (incompleteReport) { // append app/device data as this is unlikely to change between sessions
             NSDictionary *sysInfo = [BSG_KSSystemInfo systemInfo];
@@ -109,7 +112,7 @@ - (void)filterReports:(NSArray *)reports
 
     if (bugsnagReports.count == 0) {
         if (onCompletion) {
-            onCompletion(bugsnagReports, YES, nil);
+            onCompletion(bugsnagReports.count, YES, nil);
         }
         return;
     }
@@ -120,7 +123,7 @@ - (void)filterReports:(NSArray *)reports
 #pragma clang diagnostic ignored "-Wdeprecated-declarations"
     for (BugsnagBeforeNotifyHook hook in configuration.beforeNotifyHooks) {
         if (reportData) {
-            reportData = hook(reports, reportData);
+            reportData = hook(bugsnagReports, reportData);
         } else {
             break;
         }
@@ -129,16 +132,16 @@ - (void)filterReports:(NSArray *)reports
 
     if (reportData == nil) {
         if (onCompletion) {
-            onCompletion(@[], YES, nil);
+            onCompletion(0, YES, nil);
         }
         return;
     }
 
-    [self.apiClient sendData:bugsnagReports
-                 withPayload:reportData
-                       toURL:configuration.notifyURL
-            headers:[configuration errorApiHeaders]
-                onCompletion:onCompletion];
+    [self.apiClient sendItems:bugsnagReports.count
+                  withPayload:reportData
+                        toURL:configuration.notifyURL
+                      headers:[configuration errorApiHeaders]
+                 onCompletion:onCompletion];
 }
 
 
diff --git a/Source/KSCrash/Source/KSCrash/Recording/BSG_KSCrash.m b/Source/KSCrash/Source/KSCrash/Recording/BSG_KSCrash.m
index deb835d17..39e977e65 100644
--- a/Source/KSCrash/Source/KSCrash/Recording/BSG_KSCrash.m
+++ b/Source/KSCrash/Source/KSCrash/Recording/BSG_KSCrash.m
@@ -320,12 +320,12 @@ - (void)sendAllReportsWithCompletion:
     (BSG_KSCrashReportFilterCompletion)onCompletion {
     [self.crashReportStore pruneFilesLeaving:self.maxStoredReports];
 
-    NSArray *reports = [self allReports];
+    NSDictionary *reports = [self allReportsByFilename];
 
     BSG_KSLOG_INFO(@"Sending %d crash reports", [reports count]);
 
     [self sendReports:reports
-         onCompletion:^(NSArray *filteredReports, BOOL completed,
+         onCompletion:^(NSUInteger sentReportCount, BOOL completed,
                         NSError *error) {
            BSG_KSLOG_DEBUG(@"Process finished with completion: %d", completed);
            if (error != nil) {
@@ -336,7 +336,7 @@ - (void)sendAllReportsWithCompletion:
                self.deleteBehaviorAfterSendAll == BSG_KSCDeleteAlways) {
                [self deleteAllReports];
            }
-           bsg_kscrash_i_callCompletion(onCompletion, filteredReports,
+           bsg_kscrash_i_callCompletion(onCompletion, sentReportCount,
                                         completed, error);
          }];
 }
@@ -357,6 +357,7 @@ - (void)reportUserException:(NSString *)name
     const char *cName = [name cStringUsingEncoding:NSUTF8StringEncoding];
     const char *cReason = [reason cStringUsingEncoding:NSUTF8StringEncoding];
     bsg_kscrash_reportUserException(cName, cReason,
+                                    [handledState[@"severity"] UTF8String],
                                     [self encodeAsJSONString:handledState],
                                     [self encodeAsJSONString:overrides],
                                     [self encodeAsJSONString:metadata],
@@ -404,16 +405,16 @@ - (NSString *)crashReportsPath {
     return self.crashReportStore.path;
 }
 
-- (void)sendReports:(NSArray *)reports
+- (void)sendReports:(NSDictionary <NSString *, NSDictionary *> *)reports
        onCompletion:(BSG_KSCrashReportFilterCompletion)onCompletion {
     if ([reports count] == 0) {
-        bsg_kscrash_i_callCompletion(onCompletion, reports, YES, nil);
+        bsg_kscrash_i_callCompletion(onCompletion, 0, YES, nil);
         return;
     }
 
     if (self.sink == nil) {
         bsg_kscrash_i_callCompletion(
-            onCompletion, reports, NO,
+            onCompletion, 0, NO,
             [NSError bsg_errorWithDomain:[[self class] description]
                                     code:0
                              description:@"No sink set. Crash reports not sent."]);
@@ -421,9 +422,9 @@ - (void)sendReports:(NSArray *)reports
     }
 
     [self.sink filterReports:reports
-                onCompletion:^(NSArray *filteredReports, BOOL completed,
+                onCompletion:^(NSUInteger sentReportCount, BOOL completed,
                                NSError *error) {
-                  bsg_kscrash_i_callCompletion(onCompletion, filteredReports,
+                  bsg_kscrash_i_callCompletion(onCompletion, sentReportCount,
                                                completed, error);
                 }];
 }
@@ -432,6 +433,10 @@ - (NSArray *)allReports {
     return [self.crashReportStore allFiles];
 }
 
+- (NSDictionary <NSString *, NSDictionary *> *)allReportsByFilename {
+    return [self.crashReportStore allFilesByName];
+}
+
 - (BOOL)redirectConsoleLogsToFile:(NSString *)fullPath
                         overwrite:(BOOL)overwrite {
     if (bsg_kslog_setLogFilename([fullPath UTF8String], overwrite)) {
diff --git a/Source/KSCrash/Source/KSCrash/Recording/BSG_KSCrashAdvanced.h b/Source/KSCrash/Source/KSCrash/Recording/BSG_KSCrashAdvanced.h
index 82692373e..24682d038 100644
--- a/Source/KSCrash/Source/KSCrash/Recording/BSG_KSCrashAdvanced.h
+++ b/Source/KSCrash/Source/KSCrash/Recording/BSG_KSCrashAdvanced.h
@@ -85,6 +85,10 @@ typedef enum {
  */
 - (NSArray *)allReports;
 
+/** Get all reports as dictionaries, indexed by file name.
+ */
+- (NSDictionary <NSString *, NSDictionary *> *)allReportsByFilename;
+
 #pragma mark - Configuration -
 
 /** Init BSG_KSCrash instance with custom report files directory path. */
@@ -156,7 +160,7 @@ typedef enum {
  * @param reports The reports to send.
  * @param onCompletion Called when sending is complete (nil = ignore).
  */
-- (void)sendReports:(NSArray *)reports
+- (void)sendReports:(NSDictionary <NSString *, NSDictionary *> *)reports
        onCompletion:(BSG_KSCrashReportFilterCompletion)onCompletion;
 
 @end
diff --git a/Source/KSCrash/Source/KSCrash/Recording/BSG_KSCrashC.c b/Source/KSCrash/Source/KSCrash/Recording/BSG_KSCrashC.c
index 1ebc3a93b..0165b7de5 100644
--- a/Source/KSCrash/Source/KSCrash/Recording/BSG_KSCrashC.c
+++ b/Source/KSCrash/Source/KSCrash/Recording/BSG_KSCrashC.c
@@ -63,11 +63,53 @@ static char *bsg_g_stateFilePath;
 // ============================================================================
 #pragma mark - Utility -
 // ============================================================================
+static const int bsg_filepath_len = 512;
+static const int bsg_error_class_filepath_len = 21;
+static const char bsg_filepath_context_sep = '-';
 
 static inline BSG_KSCrash_Context *crashContext(void) {
     return &bsg_g_crashReportContext;
 }
 
+int bsg_create_filepath(char *base, char filepath[bsg_filepath_len], char severity, char error_class[bsg_error_class_filepath_len]) {
+    int length;
+    for (length = 0; length < bsg_filepath_len; length++) {
+        if (base[length] == '\0') {
+            break;
+        }
+        filepath[length] = base[length];
+    }
+    if (length > 5) // Remove initial .json from path
+        length -= 5;
+
+    // append contextual info
+    BSG_KSCrash_Context *context = crashContext();
+    filepath[length++] = bsg_filepath_context_sep;
+    filepath[length++] = severity;
+    filepath[length++] = bsg_filepath_context_sep;
+    // 'h' for handled vs 'u'nhandled
+    filepath[length++] = context->crash.crashType == BSG_KSCrashTypeUserReported ? 'h' : 'u';
+    filepath[length++] = bsg_filepath_context_sep;
+    for (int i = 0; error_class != NULL && i < bsg_error_class_filepath_len; i++) {
+        char c = error_class[i];
+        if (c == '\0')
+            break;
+        else if (c == 47 || c > 126 || c <= 0)
+            // disallow '/' and characters outside of the ascii range
+            continue;
+        filepath[length++] = c;
+    }
+    // add suffix
+    filepath[length++] = '.';
+    filepath[length++] = 'j';
+    filepath[length++] = 's';
+    filepath[length++] = 'o';
+    filepath[length++] = 'n';
+    filepath[length++] = '\0';
+
+    return length;
+}
+
 // ============================================================================
 #pragma mark - Callbacks -
 // ============================================================================
@@ -78,7 +120,7 @@ static inline BSG_KSCrash_Context *crashContext(void) {
  *
  * This function gets passed as a callback to a crash handler.
  */
-void bsg_kscrash_i_onCrash(void) {
+void bsg_kscrash_i_onCrash(char severity, char *errorClass) {
     BSG_KSLOG_DEBUG("Updating application state to note crash.");
     bsg_kscrashstate_notifyAppCrash();
 
@@ -92,8 +134,9 @@ void bsg_kscrash_i_onCrash(void) {
         bsg_kscrashreport_writeMinimalReport(context,
                                              bsg_g_recrashReportFilePath);
     } else {
-        bsg_kscrashreport_writeStandardReport(context,
-                                              bsg_g_crashReportFilePath);
+        char filepath[bsg_filepath_len];
+        bsg_create_filepath(bsg_g_crashReportFilePath, filepath, severity, errorClass);
+        bsg_kscrashreport_writeStandardReport(context, filepath);
     }
 }
 
@@ -242,6 +285,7 @@ void bsg_kscrash_setCrashNotifyCallback(
 }
 
 void bsg_kscrash_reportUserException(const char *name, const char *reason,
+                                     const char *severity,
                                      const char *handledState,
                                      const char *overrides,
                                      const char *metadata,
@@ -249,7 +293,7 @@ void bsg_kscrash_reportUserException(const char *name, const char *reason,
                                      const char *config,
                                      int discardDepth,
                                      bool terminateProgram) {
-    bsg_kscrashsentry_reportUserException(name, reason, handledState, overrides,
+    bsg_kscrashsentry_reportUserException(name, reason, severity, handledState, overrides,
                                           metadata, appState, config, discardDepth,
                                           terminateProgram);
 }
diff --git a/Source/KSCrash/Source/KSCrash/Recording/BSG_KSCrashC.h b/Source/KSCrash/Source/KSCrash/Recording/BSG_KSCrashC.h
index 9df924549..2aeb81cc8 100644
--- a/Source/KSCrash/Source/KSCrash/Recording/BSG_KSCrashC.h
+++ b/Source/KSCrash/Source/KSCrash/Recording/BSG_KSCrashC.h
@@ -187,6 +187,7 @@ void bsg_kscrash_setCrashNotifyCallback(
  * Terminate the program instead.
  */
 void bsg_kscrash_reportUserException(const char *name, const char *reason,
+                                     const char *severity,
                                      const char *handledState,
                                      const char *overrides,
                                      const char *metadata,
diff --git a/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry.c b/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry.c
index a2cc2d98c..50b0bd1cd 100644
--- a/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry.c
+++ b/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry.c
@@ -96,7 +96,7 @@ static bool bsg_g_threads_are_running = true;
 BSG_KSCrashType
 bsg_kscrashsentry_installWithContext(BSG_KSCrash_SentryContext *context,
                                      BSG_KSCrashType crashTypes,
-                                     void (*onCrash)(void)) {
+                                     void (*onCrash)(char, char *)) {
     if (bsg_ksmachisBeingTraced()) {
         if (context->reportWhenDebuggerIsAttached) {
             BSG_KSLOG_WARN("KSCrash: App is running in a debugger. Crash "
@@ -206,7 +206,7 @@ void bsg_kscrashsentry_resumeThreads(void) {
 }
 
 void bsg_kscrashsentry_clearContext(BSG_KSCrash_SentryContext *context) {
-    void (*onCrash)(void) = context->onCrash;
+    void (*onCrash)(char, char *) = context->onCrash;
     bool threadTracingEnabled = context->threadTracingEnabled;
     bool reportWhenDebuggerIsAttached = context->reportWhenDebuggerIsAttached;
     bool suspendThreadsForUserReported = context->suspendThreadsForUserReported;
diff --git a/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry.h b/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry.h
index 1e8e73311..b6d51008e 100644
--- a/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry.h
+++ b/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry.h
@@ -51,7 +51,7 @@ typedef struct BSG_KSCrash_SentryContext {
     // Caller defined values. Caller must fill these out prior to installation.
 
     /** Called by the crash handler when a crash is detected. */
-    void (*onCrash)(void);
+    void (*onCrash)(char, char[21]);
 
     /** If true, will suspend threads for user reported exceptions. */
     bool suspendThreadsForUserReported;
@@ -162,7 +162,7 @@ typedef struct BSG_KSCrash_SentryContext {
 BSG_KSCrashType
 bsg_kscrashsentry_installWithContext(BSG_KSCrash_SentryContext *context,
                                      BSG_KSCrashType crashTypes,
-                                     void (*onCrash)(void));
+                                     void (*onCrash)(char, char *));
 
 /** Uninstall crash sentry.
  *
diff --git a/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_CPPException.mm b/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_CPPException.mm
index f7de5f039..1456c83d2 100644
--- a/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_CPPException.mm
+++ b/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_CPPException.mm
@@ -179,7 +179,9 @@ static void CPPExceptionTerminate(void) {
         bsg_g_context->crashReason = description;
 
         BSG_KSLOG_DEBUG(@"Calling main crash handler.");
-        bsg_g_context->onCrash();
+        char errorClass[21];
+        strncpy(errorClass, bsg_g_context->CPPException.name, sizeof(errorClass));
+        bsg_g_context->onCrash('e', errorClass);
 
         BSG_KSLOG_DEBUG(
             @"Crash handling complete. Restoring original handlers.");
diff --git a/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_Deadlock.m b/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_Deadlock.m
index cb7e5b0bf..29706dd53 100644
--- a/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_Deadlock.m
+++ b/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_Deadlock.m
@@ -114,7 +114,7 @@ - (void)handleDeadlock {
     bsg_g_context->registersAreValid = false;
 
     BSG_KSLOG_DEBUG(@"Calling main crash handler.");
-    bsg_g_context->onCrash();
+    bsg_g_context->onCrash('e', "");
 
     BSG_KSLOG_DEBUG(@"Crash handling complete. Restoring original handlers.");
     bsg_kscrashsentry_uninstall(BSG_KSCrashTypeAll);
diff --git a/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_MachException.c b/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_MachException.c
index 146ee01d6..5ce551ba9 100644
--- a/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_MachException.c
+++ b/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_MachException.c
@@ -285,7 +285,9 @@ void *ksmachexc_i_handleExceptions(void *const userData) {
         bsg_g_context->mach.subcode = exceptionMessage.code[1];
 
         BSG_KSLOG_DEBUG("Calling main crash handler.");
-        bsg_g_context->onCrash();
+        char errorClass[21];
+        strncpy(errorClass, bsg_ksmachexceptionName(bsg_g_context->mach.type), sizeof(errorClass));
+        bsg_g_context->onCrash('e', errorClass);
 
         BSG_KSLOG_DEBUG(
             "Crash handling complete. Restoring original handlers.");
diff --git a/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_NSException.m b/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_NSException.m
index b72084eb4..10a46fb0c 100644
--- a/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_NSException.m
+++ b/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_NSException.m
@@ -128,7 +128,9 @@ void bsg_recordException(NSException *exception) {
         bsg_g_context->stackTraceLength = (int)numFrames;
 
         BSG_KSLOG_DEBUG(@"Calling main crash handler.");
-        bsg_g_context->onCrash();
+        char errorClass[21];
+        strncpy(errorClass, bsg_g_context->NSException.name, sizeof(errorClass));
+        bsg_g_context->onCrash('e', errorClass);
     }
 }
 
diff --git a/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_Signal.c b/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_Signal.c
index 51bf8a2ea..1cc26f8eb 100644
--- a/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_Signal.c
+++ b/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_Signal.c
@@ -107,7 +107,18 @@ void bsg_kssighndl_i_handleSignal(int sigNum, siginfo_t *signalInfo,
         bsg_g_context->signal.signalInfo = signalInfo;
 
         BSG_KSLOG_DEBUG("Calling main crash handler.");
-        bsg_g_context->onCrash();
+        char errorClass[21];
+        const char *sigName = bsg_kssignal_signalName(sigNum);
+        if (sigName != NULL) {
+            for (int i = 0; i < sizeof(errorClass); i++) {
+                char c = sigName[i];
+                if (c == '\0') {
+                    break;
+                }
+                errorClass[i] = c;
+            }
+        }
+        bsg_g_context->onCrash('e', errorClass);
 
         BSG_KSLOG_DEBUG(
             "Crash handling complete. Restoring original handlers.");
diff --git a/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_User.c b/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_User.c
index fddd69917..aa247955c 100644
--- a/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_User.c
+++ b/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_User.c
@@ -48,6 +48,7 @@ void bsg_kscrashsentry_uninstallUserExceptionHandler(void) {
 }
 
 void bsg_kscrashsentry_reportUserException(const char *name, const char *reason,
+                                           const char *severity,
                                            const char *handledState,
                                            const char *overrides,
                                            const char *metadata,
@@ -92,7 +93,9 @@ void bsg_kscrashsentry_reportUserException(const char *name, const char *reason,
         bsg_g_context->userException.state = appState;
 
         BSG_KSLOG_DEBUG("Calling main crash handler.");
-        bsg_g_context->onCrash();
+        char errorClass[21];
+        strncpy(errorClass, bsg_g_context->userException.name, sizeof(errorClass));
+        bsg_g_context->onCrash(strlen(severity) > 0 ? severity[0] : 'w', errorClass);
 
         if (terminateProgram) {
             bsg_kscrashsentry_uninstall(BSG_KSCrashTypeAll);
diff --git a/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_User.h b/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_User.h
index 103f33823..f68f583e9 100644
--- a/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_User.h
+++ b/Source/KSCrash/Source/KSCrash/Recording/Sentry/BSG_KSCrashSentry_User.h
@@ -67,6 +67,7 @@ void bsg_kscrashsentry_uninstallUserExceptionHandler(void);
  * Terminate the program instead.
  */
     void bsg_kscrashsentry_reportUserException(const char *name, const char *reason,
+                                               const char *severity,
                                                const char *handledState,
                                                const char *overrides,
                                                const char *metadata,
diff --git a/Source/KSCrash/Source/KSCrash/Recording/Tools/BSG_KSCrashCallCompletion.h b/Source/KSCrash/Source/KSCrash/Recording/Tools/BSG_KSCrashCallCompletion.h
index d212ea4c7..bc0471720 100644
--- a/Source/KSCrash/Source/KSCrash/Recording/Tools/BSG_KSCrashCallCompletion.h
+++ b/Source/KSCrash/Source/KSCrash/Recording/Tools/BSG_KSCrashCallCompletion.h
@@ -29,10 +29,10 @@
 /** Conditionally call a completion method if it's not nil.
  *
  * @param onCompletion The completion block. If nil, this function does nothing.
- * @param filteredReports The parameter to send as "filteredReports".
+ * @param sentReportCount The number of reports successfully handled.
  * @param completed The parameter to send as "completed".
  * @param error The parameter to send as "error".
  */
 void bsg_kscrash_i_callCompletion(
-    BSG_KSCrashReportFilterCompletion onCompletion, NSArray *filteredReports,
+    BSG_KSCrashReportFilterCompletion onCompletion, NSUInteger sentReportCount,
     BOOL completed, NSError *error);
diff --git a/Source/KSCrash/Source/KSCrash/Recording/Tools/BSG_KSCrashCallCompletion.m b/Source/KSCrash/Source/KSCrash/Recording/Tools/BSG_KSCrashCallCompletion.m
index 7a7f2027d..181bdbb02 100644
--- a/Source/KSCrash/Source/KSCrash/Recording/Tools/BSG_KSCrashCallCompletion.m
+++ b/Source/KSCrash/Source/KSCrash/Recording/Tools/BSG_KSCrashCallCompletion.m
@@ -27,9 +27,9 @@
 #import "BSG_KSCrashCallCompletion.h"
 
 void bsg_kscrash_i_callCompletion(
-    BSG_KSCrashReportFilterCompletion onCompletion, NSArray *filteredReports,
+    BSG_KSCrashReportFilterCompletion onCompletion, NSUInteger reportCount,
     BOOL completed, NSError *error) {
     if (onCompletion) {
-        onCompletion(filteredReports, completed, error);
+        onCompletion(reportCount, completed, error);
     }
 }
diff --git a/Source/KSCrash/Source/KSCrash/Reporting/Filters/BSG_KSCrashReportFilter.h b/Source/KSCrash/Source/KSCrash/Reporting/Filters/BSG_KSCrashReportFilter.h
index f09806c51..7f73fa20c 100644
--- a/Source/KSCrash/Source/KSCrash/Reporting/Filters/BSG_KSCrashReportFilter.h
+++ b/Source/KSCrash/Source/KSCrash/Reporting/Filters/BSG_KSCrashReportFilter.h
@@ -37,7 +37,7 @@
  * @param reports The reports to process.
  * @param onCompletion Block to call when processing is complete.
  */
-- (void)filterReports:(NSArray *)reports
+- (void)filterReports:(NSDictionary <NSString *, NSDictionary *> *)reports
          onCompletion:(BSG_KSCrashReportFilterCompletion)onCompletion;
 
 @end
diff --git a/Source/KSCrash/Source/KSCrash/Reporting/Filters/BSG_KSCrashReportFilterCompletion.h b/Source/KSCrash/Source/KSCrash/Reporting/Filters/BSG_KSCrashReportFilterCompletion.h
index 9462707dd..19177ad85 100644
--- a/Source/KSCrash/Source/KSCrash/Reporting/Filters/BSG_KSCrashReportFilterCompletion.h
+++ b/Source/KSCrash/Source/KSCrash/Reporting/Filters/BSG_KSCrashReportFilterCompletion.h
@@ -28,13 +28,12 @@
 
 /** Callback for filter operations.
  *
- * @param filteredReports The filtered reports (may be incomplete if "completed"
- *                        is false).
+ * @param sentReportCount The number of reports successfully sent.
  * @param completed True if filtering completed.
  *                  Can be false due to a non-erroneous condition (such as a
  *                  user cancelling the operation).
  * @param error Non-nil if an error occurred.
  */
-typedef void (^BSG_KSCrashReportFilterCompletion)(NSArray *filteredReports,
+typedef void (^BSG_KSCrashReportFilterCompletion)(NSUInteger sentReportCount,
                                                   BOOL completed,
                                                   NSError *error);
diff --git a/Tests/BSGFilepathTests.m b/Tests/BSGFilepathTests.m
new file mode 100644
index 000000000..31416eec1
--- /dev/null
+++ b/Tests/BSGFilepathTests.m
@@ -0,0 +1,64 @@
+//
+//  BSGFilepathTests.m
+//  Tests
+//
+//  Created by Delisa on 2/19/19.
+//  Copyright © 2019 Bugsnag. All rights reserved.
+//
+
+#import <XCTest/XCTest.h>
+#include <string.h>
+
+
+int bsg_create_filepath(char *base, char filepath[512], char severity, char error_class[21]);
+
+@interface BSGFilepathTests : XCTestCase
+
+@end
+
+@implementation BSGFilepathTests
+
+- (void)testEncodeCharacters {
+    char *base = "/path/to/it/imagine this is a UUID.json";
+    char filepath[512];
+    bsg_create_filepath(base, filepath, 'w', "😃 HappyError");
+    XCTAssertEqual(0, strcmp(filepath, "/path/to/it/imagine this is a UUID-w-u- HappyError.json"));
+}
+
+- (void)testTruncateUnicodeCharacters {
+    char *base = "/path/to/it/imagine this is a UUID.json";
+    char filepath[512];
+    // The char limit is not on a character boundary
+    bsg_create_filepath(base, filepath, 'e', "AnExtremelyLongLong😃");
+    XCTAssertEqual(0, strcmp(filepath, "/path/to/it/imagine this is a UUID-e-u-AnExtremelyLongLong.json"));
+}
+
+- (void)testNullErrorClass {
+    char *base = "/path/to/it/imagine this is a UUID.json";
+    char filepath[512];
+    bsg_create_filepath(base, filepath, 'e', NULL);
+    XCTAssertEqual(0, strcmp(filepath, "/path/to/it/imagine this is a UUID-e-u-.json"));
+}
+
+- (void)testEmptyErrorClass {
+    char *base = "/path/to/it/imagine this is a UUID.json";
+    char filepath[512];
+    bsg_create_filepath(base, filepath, 'e', "");
+    XCTAssertEqual(0, strcmp(filepath, "/path/to/it/imagine this is a UUID-e-u-.json"));
+}
+
+- (void)testEmptyErrorClassFromUnicode {
+    char *base = "/path/to/it/imagine this is a UUID.json";
+    char filepath[512];
+    bsg_create_filepath(base, filepath, 'e', "🀦🀨🁺😃");
+    XCTAssertEqual(0, strcmp(filepath, "/path/to/it/imagine this is a UUID-e-u-.json"));
+}
+
+- (void)testErrorClassLength {
+    char *base = "imagine this is a UUID.json";
+    char filepath[512];
+    bsg_create_filepath(base, filepath, 'i', "AnExtremelyLongLongErrorNameOmg");
+    XCTAssertEqual(0, strcmp(filepath, "imagine this is a UUID-i-u-AnExtremelyLongLongEr.json"));
+}
+
+@end
diff --git a/Tests/BugsnagCrashReportTests.m b/Tests/BugsnagCrashReportTests.m
index 54cfebbbd..b69fb9bd4 100644
--- a/Tests/BugsnagCrashReportTests.m
+++ b/Tests/BugsnagCrashReportTests.m
@@ -14,6 +14,7 @@
 #import "BugsnagHandledState.h"
 #import "BugsnagSession.h"
 
+
 @interface BugsnagCrashReportTests : XCTestCase
 @property BugsnagCrashReport *report;
 @end
@@ -178,6 +179,45 @@ - (void)testDefaultErrorMessageNil {
                           payload[@"exceptions"][0][@"message"]);
 }
 
+- (void)testIncomplete {
+    XCTAssertTrue([[[BugsnagCrashReport alloc] initWithKSReport:@{}] isIncomplete]);
+    XCTAssertFalse([[[BugsnagCrashReport alloc] initWithKSReport:@{@"foo": @"bar"}] isIncomplete]);
+}
+
+- (void)testFallbackValues {
+    BugsnagCrashReport *report =
+        [[BugsnagCrashReport alloc] initWithKSReport:@{} fileMetadata:@"w-h-SomeErr thing"];
+    XCTAssertTrue([report isIncomplete]);
+    NSDictionary *payload = [report toJson];
+    XCTAssertEqualObjects(@"SomeErr thing", payload[@"exceptions"][0][@"errorClass"]);
+    XCTAssertEqualObjects(@"warning", payload[@"severity"]);
+    XCTAssertEqualObjects(@NO, payload[@"unhandled"]);
+}
+
+- (void)testUnneededFallbackValues {
+    BugsnagHandledState *state = [BugsnagHandledState handledStateWithSeverityReason:UserCallbackSetSeverity
+                                                                            severity:BSGSeverityInfo
+                                                                           attrValue:nil];
+    NSDictionary *dict = @{@"user.handledState": [state toJson]};
+    BugsnagCrashReport *report =
+        [[BugsnagCrashReport alloc] initWithKSReport:dict fileMetadata:@"w-h-SomeErr thing"];
+    XCTAssertFalse([report isIncomplete]);
+    NSDictionary *payload = [report toJson];
+    XCTAssertEqualObjects(@"SomeErr thing", payload[@"exceptions"][0][@"errorClass"]);
+    XCTAssertEqualObjects(@"info", payload[@"severity"]);
+    XCTAssertEqualObjects(@NO, payload[@"unhandled"]);
+}
+
+- (void)testUnhandledFallbackValues {
+    BugsnagCrashReport *report =
+    [[BugsnagCrashReport alloc] initWithKSReport:@{} fileMetadata:@"foofoo-e-u-SomeErr thing"];
+    XCTAssertTrue([report isIncomplete]);
+    NSDictionary *payload = [report toJson];
+    XCTAssertEqualObjects(@"SomeErr thing", payload[@"exceptions"][0][@"errorClass"]);
+    XCTAssertEqualObjects(@"error", payload[@"severity"]);
+    XCTAssertEqualObjects(@YES, payload[@"unhandled"]);
+}
+
 - (void)testDefaultErrorMessageNilForEmptyThreads {
     BugsnagCrashReport *report = [[BugsnagCrashReport alloc] initWithKSReport:@{
         @"threads" : @[]
@@ -533,5 +573,4 @@ - (void)testAppVersionOverride {
     XCTAssertEqualObjects(@"1.2.3", dictionary[@"app"][@"version"]);
 }
 
-
 @end
diff --git a/Tests/KSCrash/KSCrashSentry_Tests.m b/Tests/KSCrash/KSCrashSentry_Tests.m
index 6c0f1829a..1b165b79d 100755
--- a/Tests/KSCrash/KSCrashSentry_Tests.m
+++ b/Tests/KSCrash/KSCrashSentry_Tests.m
@@ -30,7 +30,7 @@
 #import "BSG_KSCrashSentry.h"
 #import "BSG_KSCrashSentry_Private.h"
 
-static void onCrash(void)
+static void onCrash(char severity, char *errorClass)
 {
     // Do nothing
 }
diff --git a/features/crashprobe.feature b/features/crashprobe.feature
index d119c9612..d8b054959 100644
--- a/features/crashprobe.feature
+++ b/features/crashprobe.feature
@@ -218,3 +218,15 @@ Scenario: Access a non-object as an object
     And the exception "message" equals "Attempted to dereference garbage pointer 0x10."
     And the exception "errorClass" equals "EXC_BAD_ACCESS"
     And the "method" of stack frame 0 equals "objc_msgSend"
+
+Scenario: Crash report file corruption
+    When I set environment variable "BUGSNAG_API_KEY" to "a35a2a72bd230ac0aa0f52715bbdc6aa"
+    And I crash the app using "AccessNonObjectScenario"
+    And I corrupt all reports on disk
+    And I relaunch the app
+    Then I should receive a request
+    And the request is a valid for the error reporting API
+    And the exception "errorClass" equals "EXC_BAD_ACCESS"
+    And the event "unhandled" is true
+    And the event "incomplete" is true
+    And the event "severity" equals "error"
diff --git a/features/steps/ios_steps.rb b/features/steps/ios_steps.rb
index 9766630f3..e71eda56f 100644
--- a/features/steps/ios_steps.rb
+++ b/features/steps/ios_steps.rb
@@ -43,6 +43,15 @@
   assert_not_equal(value1, value2)
 end
 
+When("I corrupt all reports on disk") do
+  app_path = `xcrun simctl get_app_container booted com.bugsnag.iOSTestApp`.chomp
+  app_path.gsub!(/(.*Containers).*/, '\1')
+  files = Dir.glob("#{app_path}/**/KSCrashReports/iOSTestApp/*.json")
+  files.each do |path|
+    File.open(path, 'w') {|file| file.truncate(0) }
+  end
+end
+
 Then("each event in the payload for request {int} matches one of:") do |request_index, table|
   events = read_key_path(find_request(request_index)[:body], "events")
   table.hashes.each do |values|
diff --git a/iOS/Bugsnag.xcodeproj/project.pbxproj b/iOS/Bugsnag.xcodeproj/project.pbxproj
index d8cc3ea44..e9d60fcb2 100644
--- a/iOS/Bugsnag.xcodeproj/project.pbxproj
+++ b/iOS/Bugsnag.xcodeproj/project.pbxproj
@@ -7,6 +7,7 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		8A12006A221C36420008C9C3 /* BSGFilepathTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 8A120069221C36420008C9C3 /* BSGFilepathTests.m */; };
 		8A2C8F231C6BBD2300846019 /* Bugsnag.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 8A2C8F181C6BBD2300846019 /* Bugsnag.framework */; };
 		8A2C8F4F1C6BBE3C00846019 /* Bugsnag.h in Headers */ = {isa = PBXBuildFile; fileRef = 8A2C8F3D1C6BBE3C00846019 /* Bugsnag.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		8A2C8F501C6BBE3C00846019 /* Bugsnag.m in Sources */ = {isa = PBXBuildFile; fileRef = 8A2C8F3E1C6BBE3C00846019 /* Bugsnag.m */; };
@@ -410,6 +411,7 @@
 /* End PBXCopyFilesBuildPhase section */
 
 /* Begin PBXFileReference section */
+		8A120069221C36420008C9C3 /* BSGFilepathTests.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; name = BSGFilepathTests.m; path = ../../Tests/BSGFilepathTests.m; sourceTree = "<group>"; };
 		8A2C8F181C6BBD2300846019 /* Bugsnag.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = Bugsnag.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		8A2C8F1D1C6BBD2300846019 /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = SOURCE_ROOT; };
 		8A2C8F221C6BBD2300846019 /* Tests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = Tests.xctest; sourceTree = BUILT_PRODUCTS_DIR; };
@@ -732,6 +734,7 @@
 				F429554A50F3ABE60537F70E /* BugsnagKSCrashSysInfoParserTest.m */,
 				F42954B7D892334E7551F0F3 /* RegisterErrorDataTest.m */,
 				F429551527EAE3AFE1F605FE /* BugsnagThreadTest.m */,
+				8A120069221C36420008C9C3 /* BSGFilepathTests.m */,
 			);
 			name = Tests;
 			path = BugsnagTests;
@@ -1244,6 +1247,7 @@
 				E78C1EF11FCC2F1700B976D3 /* BugsnagSessionTrackerTest.m in Sources */,
 				F4295995C3259BF7D9730BC4 /* BugsnagKSCrashSysInfoParserTest.m in Sources */,
 				F4295F017754324FD52CCE46 /* RegisterErrorDataTest.m in Sources */,
+				8A12006A221C36420008C9C3 /* BSGFilepathTests.m in Sources */,
 				F42952D83435C02F8D891C40 /* BugsnagThreadTest.m in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
diff --git a/tvOS/Bugsnag.xcodeproj/project.pbxproj b/tvOS/Bugsnag.xcodeproj/project.pbxproj
index 5f1f9aeb8..e1d3c867b 100644
--- a/tvOS/Bugsnag.xcodeproj/project.pbxproj
+++ b/tvOS/Bugsnag.xcodeproj/project.pbxproj
@@ -7,6 +7,7 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		8A12006E221C51550008C9C3 /* BSGFilepathTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 8A12006D221C51550008C9C3 /* BSGFilepathTests.m */; };
 		8A48EF291EAA824100B70024 /* BugsnagLogger.h in Headers */ = {isa = PBXBuildFile; fileRef = 8A48EF281EAA824100B70024 /* BugsnagLogger.h */; };
 		8A627CD51EC3B69300F7C04E /* BSGSerialization.h in Headers */ = {isa = PBXBuildFile; fileRef = 8A627CD31EC3B69300F7C04E /* BSGSerialization.h */; };
 		8A627CD61EC3B69300F7C04E /* BSGSerialization.m in Sources */ = {isa = PBXBuildFile; fileRef = 8A627CD41EC3B69300F7C04E /* BSGSerialization.m */; };
@@ -187,6 +188,7 @@
 /* End PBXContainerItemProxy section */
 
 /* Begin PBXFileReference section */
+		8A12006D221C51550008C9C3 /* BSGFilepathTests.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = BSGFilepathTests.m; path = ../../Tests/BSGFilepathTests.m; sourceTree = "<group>"; };
 		8A48EF281EAA824100B70024 /* BugsnagLogger.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = BugsnagLogger.h; path = ../Source/BugsnagLogger.h; sourceTree = "<group>"; };
 		8A627CD31EC3B69300F7C04E /* BSGSerialization.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = BSGSerialization.h; path = ../Source/BSGSerialization.h; sourceTree = "<group>"; };
 		8A627CD41EC3B69300F7C04E /* BSGSerialization.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = BSGSerialization.m; path = ../Source/BSGSerialization.m; sourceTree = "<group>"; };
@@ -465,6 +467,7 @@
 			isa = PBXGroup;
 			children = (
 				E7CE78D71FD94EF1001D07E0 /* KSCrash */,
+				8A12006D221C51550008C9C3 /* BSGFilepathTests.m */,
 				E791488C1FD82E77003EFEBF /* BugsnagSessionTest.m */,
 				E791488A1FD82E77003EFEBF /* BugsnagSessionTrackerTest.m */,
 				E791488B1FD82E77003EFEBF /* BugsnagSessionTrackingPayloadTest.m */,
@@ -941,6 +944,7 @@
 				E7CE79051FD94F1B001D07E0 /* KSDynamicLinker_Tests.m in Sources */,
 				E7CE78F61FD94F1B001D07E0 /* FileBasedTestCase.m in Sources */,
 				E7CE79031FD94F1B001D07E0 /* KSCrashReportConverter_Tests.m in Sources */,
+				8A12006E221C51550008C9C3 /* BSGFilepathTests.m in Sources */,
 				E79148911FD82E77003EFEBF /* BugsnagUserTest.m in Sources */,
 				E791488E1FD82E77003EFEBF /* BugsnagSessionTrackerTest.m in Sources */,
 				E79148901FD82E77003EFEBF /* BugsnagSessionTest.m in Sources */,