diff --git a/sources/src/main/java/com/ullink/slack/simpleslackapi/SlackPreparedMessage.java b/sources/src/main/java/com/ullink/slack/simpleslackapi/SlackPreparedMessage.java
index 288e11c0..b08b3773 100644
--- a/sources/src/main/java/com/ullink/slack/simpleslackapi/SlackPreparedMessage.java
+++ b/sources/src/main/java/com/ullink/slack/simpleslackapi/SlackPreparedMessage.java
@@ -7,18 +7,20 @@
 import java.util.Objects;
 
 public class SlackPreparedMessage {
+
     private String message;
     private boolean unfurl;
     private boolean linkNames;
-    private SlackAttachment[] attachments;
+    private List<SlackAttachment> attachments;
     private String threadTimestamp;
     private boolean replyBroadcast;
 
+
     private SlackPreparedMessage(String message, boolean unfurl, boolean linkNames, SlackAttachment[] attachments, String threadTimestamp, boolean replyBroadcast) {
         this.message = message;
         this.unfurl = unfurl;
         this.linkNames = linkNames;
-        this.attachments = attachments;
+        this.attachments = Arrays.asList(attachments);
         this.threadTimestamp = threadTimestamp;
         this.replyBroadcast = replyBroadcast;
     }
@@ -40,7 +42,7 @@ public boolean isLinkNames() {
     }
 
     public SlackAttachment[] getAttachments() {
-        return attachments;
+        return attachments.toArray(new SlackAttachment[]{});
     }
 
     public String getThreadTimestamp() {
@@ -125,7 +127,7 @@ public String toString() {
         return "SlackPreparedMessage{" +
                 "message='" + message + '\'' +
                 ", unfurl=" + unfurl +
-                ", attachments=" + Arrays.toString(attachments) +
+                ", attachments=" + attachments +
                 '}';
     }
 
diff --git a/sources/src/main/java/com/ullink/slack/simpleslackapi/impl/ChannelHistoryModuleImpl.java b/sources/src/main/java/com/ullink/slack/simpleslackapi/impl/ChannelHistoryModuleImpl.java
index 1b451dfc..042f556d 100644
--- a/sources/src/main/java/com/ullink/slack/simpleslackapi/impl/ChannelHistoryModuleImpl.java
+++ b/sources/src/main/java/com/ullink/slack/simpleslackapi/impl/ChannelHistoryModuleImpl.java
@@ -159,7 +159,7 @@ public List<SlackMessagePosted> fetchUpdatingHistoryOfChannel(String channelId,
         return messages;
     }
 
-    public class ChannelHistoryReactionAddedListener implements ReactionAddedListener {
+    public static class ChannelHistoryReactionAddedListener implements ReactionAddedListener {
 
         List<SlackMessagePosted> messages = new ArrayList<>();
 
@@ -174,7 +174,7 @@ public void onEvent(ReactionAdded event, SlackSession session) {
                 for (String reaction : message.getReactions().keySet()) {
                     if (emojiName.equals(reaction)) {
                         int count = message.getReactions().get(emojiName);
-                        message.getReactions().put(emojiName, count++);
+                        message.getReactions().put(emojiName, ++count);
                         return;
                     }
                 }
@@ -183,7 +183,7 @@ public void onEvent(ReactionAdded event, SlackSession session) {
         }
     };
 
-    public class ChannelHistoryReactionRemovedListener implements ReactionRemovedListener {
+    public static class ChannelHistoryReactionRemovedListener implements ReactionRemovedListener {
 
         List<SlackMessagePosted> messages = new ArrayList<>();
 
@@ -210,7 +210,7 @@ public void onEvent(ReactionRemoved event, SlackSession session) {
         }
     }
 
-    public class ChannelHistoryMessagePostedListener implements SlackMessagePostedListener {
+    public static class ChannelHistoryMessagePostedListener implements SlackMessagePostedListener {
 
         List<SlackMessagePosted> messages = new ArrayList<>();
 
diff --git a/sources/src/main/java/com/ullink/slack/simpleslackapi/impl/SlackJSONMessageParser.java b/sources/src/main/java/com/ullink/slack/simpleslackapi/impl/SlackJSONMessageParser.java
index 7db6526f..3bbf84c8 100644
--- a/sources/src/main/java/com/ullink/slack/simpleslackapi/impl/SlackJSONMessageParser.java
+++ b/sources/src/main/java/com/ullink/slack/simpleslackapi/impl/SlackJSONMessageParser.java
@@ -12,7 +12,11 @@
 import java.util.HashMap;
 import java.util.Map;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 class SlackJSONMessageParser {
+    private static final Logger LOGGER                     = LoggerFactory.getLogger(SlackJSONMessageParser.class);
 
     public static enum SlackMessageSubType
     {
@@ -270,6 +274,7 @@ private static void parseSlackFileFromRaw(JsonObject rawFile, SlackFile file) {
             file.setImageExifRotation(GsonHelper.getLongOrNull(rawFile.get("image_exif_rotation")));
         } catch(Exception e){
             //this properties will be null if something goes wrong
+            LOGGER.error("Failed to parse slack file", e);
         }
         file.setPermalink(GsonHelper.getStringOrNull(rawFile.get("permalink")));
         file.setPermalinkPublic(GsonHelper.getStringOrNull(rawFile.get("permalink_public")));
diff --git a/sources/src/main/java/com/ullink/slack/simpleslackapi/impl/SlackJSONParsingUtils.java b/sources/src/main/java/com/ullink/slack/simpleslackapi/impl/SlackJSONParsingUtils.java
index 064c4a67..3d1b94f0 100644
--- a/sources/src/main/java/com/ullink/slack/simpleslackapi/impl/SlackJSONParsingUtils.java
+++ b/sources/src/main/java/com/ullink/slack/simpleslackapi/impl/SlackJSONParsingUtils.java
@@ -56,7 +56,7 @@ static final SlackUser buildSlackUser(JsonObject jsonUser)
         {
             slackPresence = SlackPersona.SlackPresence.AWAY;
         }
-        return new SlackUserImpl(id, name, realName, email, skype, title, phone, deleted, admin, owner, primaryOwner, restricted, ultraRestricted, bot, tz, tzLabel, tzOffset == null ? null : new Integer(tzOffset.intValue()), slackPresence);
+        return new SlackUserImpl(id, name, realName, email, skype, title, phone, deleted, admin, owner, primaryOwner, restricted, ultraRestricted, bot, tz, tzLabel, tzOffset, slackPresence);
     }
 
     static final SlackChannel buildSlackChannel(JsonObject jsonChannel, Map<String, SlackUser> knownUsersById) {
diff --git a/sources/src/main/java/com/ullink/slack/simpleslackapi/impl/SlackWebSocketSessionImpl.java b/sources/src/main/java/com/ullink/slack/simpleslackapi/impl/SlackWebSocketSessionImpl.java
index 50a06f3b..d4c6daa9 100644
--- a/sources/src/main/java/com/ullink/slack/simpleslackapi/impl/SlackWebSocketSessionImpl.java
+++ b/sources/src/main/java/com/ullink/slack/simpleslackapi/impl/SlackWebSocketSessionImpl.java
@@ -48,6 +48,7 @@
 import java.net.ConnectException;
 import java.net.Proxy;
 import java.net.URI;
+import java.nio.charset.Charset;
 import java.util.*;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicLong;
@@ -234,7 +235,7 @@ void dispatch(SlackEvent event) {
                 case USER_TYPING:
                     dispatchImpl((UserTyping) event, userTypingListener);
                     break;
-                case UNKNOWN:
+                default:
                     LOGGER.warn("event of type " + event.getEventType() + " not handled: " + ((UnknownEvent)event).getJsonPayload());
             }
         }
@@ -867,7 +868,7 @@ private void postSlackCommandWithFile(Map<String, String> params, byte [] fileCo
             builder.addBinaryBody("file",fileContent, ContentType.DEFAULT_BINARY,fileName);
             request.setEntity(builder.build());
             HttpResponse response = client.execute(request);
-            String jsonResponse = ReaderUtils.readAll(new InputStreamReader(response.getEntity().getContent()));
+            String jsonResponse = ReaderUtils.readAll(new InputStreamReader(response.getEntity().getContent(), Charset.forName("UTF-8")));
             LOGGER.debug("PostMessage return: " + jsonResponse);
             ParsedSlackReply reply = SlackJSONReplyParser.decode(parseObject(jsonResponse),this);
             handle.setReply(reply);