diff --git a/test_runner/src/main/kotlin/ftl/util/OutcomeDetailsFormatter.kt b/test_runner/src/main/kotlin/ftl/util/OutcomeDetailsFormatter.kt
index d5c47d855a..55b93766d6 100644
--- a/test_runner/src/main/kotlin/ftl/util/OutcomeDetailsFormatter.kt
+++ b/test_runner/src/main/kotlin/ftl/util/OutcomeDetailsFormatter.kt
@@ -4,7 +4,6 @@ import com.google.api.services.toolresults.model.FailureDetail
 import com.google.api.services.toolresults.model.InconclusiveDetail
 import com.google.api.services.toolresults.model.Outcome
 import com.google.api.services.toolresults.model.SkippedDetail
-import com.google.api.services.toolresults.model.SuccessDetail
 import ftl.reports.api.data.TestSuiteOverviewData
 import ftl.util.StepOutcome.failure
 import ftl.util.StepOutcome.flaky
@@ -12,10 +11,14 @@ import ftl.util.StepOutcome.inconclusive
 import ftl.util.StepOutcome.skipped
 import ftl.util.StepOutcome.success
 import ftl.util.StepOutcome.unset
-import java.lang.StringBuilder
 
 fun Outcome.getDetails(testSuiteOverviewData: TestSuiteOverviewData?) = when (summary) {
-    success, flaky -> testSuiteOverviewData?.let { getSuccessOutcomeDetails(it, successDetail) }
+    success, flaky -> testSuiteOverviewData?.let {
+        getSuccessOutcomeDetails(
+            testSuiteOverviewData = it,
+            otherNativeCrash = successDetail?.otherNativeCrash ?: false
+        )
+    }
     failure -> failureDetail.getFailureOutcomeDetails(testSuiteOverviewData)
     inconclusive -> inconclusiveDetail.formatOutcomeDetails()
     skipped -> skippedDetail.formatOutcomeDetails()
@@ -25,32 +28,31 @@ fun Outcome.getDetails(testSuiteOverviewData: TestSuiteOverviewData?) = when (su
 
 private fun getSuccessOutcomeDetails(
     testSuiteOverviewData: TestSuiteOverviewData,
-    successDetail: SuccessDetail?
+    otherNativeCrash: Boolean
 ) = StringBuilder("${testSuiteOverviewData.successCount} test cases passed").apply {
     if (testSuiteOverviewData.skipped > 0) append(skippedMessage(testSuiteOverviewData.skipped))
     if (testSuiteOverviewData.flakes > 0) append(flakesMessage(testSuiteOverviewData.flakes))
-    if (successDetail?.otherNativeCrash == true) append(NATIVE_CRASH_MESSAGE)
+    if (otherNativeCrash) append(NATIVE_CRASH_MESSAGE)
 }.toString()
 
 private val TestSuiteOverviewData.successCount
     get() = total - errors - failures - skipped - flakes
 
 private fun FailureDetail?.getFailureOutcomeDetails(testSuiteOverviewData: TestSuiteOverviewData?) = when {
-    this == null -> testSuiteOverviewData?.buildFailureOutcomeDetailsSummary()
+    this == null -> testSuiteOverviewData?.buildFailureOutcomeDetailsSummary() ?: "Unknown failure"
     crashed == true -> "Application crashed"
     timedOut == true -> "Test timed out"
     notInstalled == true -> "App failed to install"
-    else -> testSuiteOverviewData?.buildFailureOutcomeDetailsSummary()
+    else -> testSuiteOverviewData?.buildFailureOutcomeDetailsSummary() ?: "Unknown failure"
 } + this?.takeIf { it.otherNativeCrash }?.let { NATIVE_CRASH_MESSAGE }.orEmpty()
 
-private fun TestSuiteOverviewData.buildFailureOutcomeDetailsSummary(): String {
-    return StringBuilder("$failures test casess failed").apply {
+private fun TestSuiteOverviewData.buildFailureOutcomeDetailsSummary() =
+    StringBuilder("$failures test cases failed").apply {
         if (errors > 0) append(errorMessage(errors))
         successCount.takeIf { it > 0 }?.let { append(successMessage(it)) }
         if (skipped > 0) append(skippedMessage(skipped))
         if (flakes > 0) append(flakesMessage(flakes))
     }.toString()
-}
 
 private fun InconclusiveDetail?.formatOutcomeDetails() = when {
     this == null -> "Unknown reason"
diff --git a/test_runner/src/test/kotlin/ftl/util/OutcomeDetailsFormatterTest.kt b/test_runner/src/test/kotlin/ftl/util/OutcomeDetailsFormatterTest.kt
index 540a8b0d97..03fcba060b 100644
--- a/test_runner/src/test/kotlin/ftl/util/OutcomeDetailsFormatterTest.kt
+++ b/test_runner/src/test/kotlin/ftl/util/OutcomeDetailsFormatterTest.kt
@@ -63,7 +63,7 @@ internal class OutcomeDetailsFormatterTest {
             }
         }
         val testSuiteOverviewData = TestSuiteOverviewData(12, 3, 3, 3, 2, 0.0, 0.0)
-        val expectedMessage = "${testSuiteOverviewData.failures} test casess failed, " +
+        val expectedMessage = "${testSuiteOverviewData.failures} test cases failed, " +
                 "${testSuiteOverviewData.errors} errors, " +
                 "1 passed, " +
                 "${testSuiteOverviewData.skipped} skipped, " +
@@ -139,6 +139,43 @@ internal class OutcomeDetailsFormatterTest {
         assertEquals(expectedMessage, result)
     }
 
+    @Test
+    fun `Should return unknown failure message for failed-null testSuiteOverviewData`() {
+        // given
+        val mockedOutcome = mockk<Outcome> {
+            every { summary } returns StepOutcome.failure
+            every { failureDetail } returns mockk {
+                every { crashed } returns false
+                every { timedOut } returns false
+                every { notInstalled } returns false
+                every { otherNativeCrash } returns false
+            }
+        }
+        val expectedMessage = "Unknown failure"
+
+        // when
+        val result = mockedOutcome.getDetails(null)
+
+        // then
+        assertEquals(expectedMessage, result)
+    }
+
+    @Test
+    fun `Should return unknown failure message for failed-null testSuiteOverviewData and failure details present`() {
+        // given
+        val mockedOutcome = mockk<Outcome> {
+            every { summary } returns StepOutcome.failure
+            every { failureDetail } returns null
+        }
+        val expectedMessage = "Unknown failure"
+
+        // when
+        val result = mockedOutcome.getDetails(null)
+
+        // then
+        assertEquals(expectedMessage, result)
+    }
+
     @Test
     fun `should contains message about native crash when it happens`() {
         // given