diff --git a/android/CHANGELOG.md b/android/CHANGELOG.md
index 7f384e08..d613f88e 100644
--- a/android/CHANGELOG.md
+++ b/android/CHANGELOG.md
@@ -6,6 +6,13 @@ follow [https://changelog.md/](https://changelog.md/) guidelines.
 
 ## [Unreleased]
 
+## [51.6] - 2024-01-24
+
+### FIXED
+
+- A crash when trying to change password using Recovery Code
+- A probable source of crashes regarding handling of MuunHeader
+
 ## [51.6] - 2024-01-17
 
 ### FIXED
diff --git a/android/apollo/src/main/java/io/muun/apollo/domain/BackgroundTimesService.kt b/android/apollo/src/main/java/io/muun/apollo/domain/BackgroundTimesService.kt
index c5bae59b..4d5388ee 100644
--- a/android/apollo/src/main/java/io/muun/apollo/domain/BackgroundTimesService.kt
+++ b/android/apollo/src/main/java/io/muun/apollo/domain/BackgroundTimesService.kt
@@ -1,5 +1,6 @@
 package io.muun.apollo.domain
 
+import androidx.annotation.VisibleForTesting
 import io.muun.apollo.data.preferences.BackgroundTimesRepository
 import javax.inject.Inject
 
@@ -7,7 +8,10 @@ class BackgroundTimesService @Inject constructor(
     private val backgroundTimesRepository: BackgroundTimesRepository,
 ) {
 
-    private val MAX_BKG_TIMES_ARRAY_SIZE: Int = 100
+    companion object {
+        @VisibleForTesting
+        val MAX_BKG_TIMES_ARRAY_SIZE: Int = 100
+    }
 
     fun enterBackground() {
         backgroundTimesRepository.recordEnterBackground()
diff --git a/android/apolloui/build.gradle b/android/apolloui/build.gradle
index 5f216e76..c266134c 100644
--- a/android/apolloui/build.gradle
+++ b/android/apolloui/build.gradle
@@ -91,8 +91,8 @@ android {
         applicationId "io.muun.apollo"
         minSdkVersion 19
         targetSdkVersion 33
-        versionCode 1106
-        versionName "51.6"
+        versionCode 1107
+        versionName "51.7"
 
         // Needed to make sure these classes are available in the main DEX file for API 19
         // See: https://spin.atomicobject.com/2018/07/16/support-kitkat-multidex/
diff --git a/android/apolloui/src/androidTest/java/io/muun/apollo/domain/BackgroundTimesServiceTest.kt b/android/apolloui/src/androidTest/java/io/muun/apollo/domain/BackgroundTimesServiceTest.kt
new file mode 100644
index 00000000..e4774017
--- /dev/null
+++ b/android/apolloui/src/androidTest/java/io/muun/apollo/domain/BackgroundTimesServiceTest.kt
@@ -0,0 +1,82 @@
+package io.muun.apollo.domain
+
+import android.content.Context
+import androidx.test.platform.app.InstrumentationRegistry
+import androidx.test.runner.AndroidJUnit4
+import io.muun.apollo.data.preferences.BackgroundTimesRepository
+import io.muun.apollo.data.preferences.RepositoryRegistry
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.After
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * @see [Testing documentation](http://d.android.com/tools/testing)
+ */
+@RunWith(AndroidJUnit4::class)
+class BackgroundTimesServiceTest {
+
+    private lateinit var context: Context
+    private lateinit var backgroundTimesService: BackgroundTimesService
+    private lateinit var backgroundTimesRepository: BackgroundTimesRepository
+
+    @Before
+    fun setUp() {
+        context = InstrumentationRegistry.getInstrumentation().targetContext
+        backgroundTimesRepository = BackgroundTimesRepository(context, RepositoryRegistry())
+        backgroundTimesService = BackgroundTimesService(
+            backgroundTimesRepository
+        )
+
+        backgroundTimesRepository.clear()
+    }
+
+    @After
+    fun cleanUp() {
+        backgroundTimesRepository.clear()
+    }
+
+    @Test
+    fun saveSingleBackgroundEventWorks() {
+        backgroundTimesService.enterBackground()
+        backgroundTimesService.enterForeground()
+
+        val bkgTimes = backgroundTimesRepository.getBackgroundTimes()
+        assertThat(bkgTimes).isNotEmpty
+        assertThat(bkgTimes.size).isEqualTo(1)
+    }
+
+    @Test
+    fun recordForegroundBeforeGoingToBackgroundDoesntStoreAnything() {
+        // E.g on first open we record enterForeground but since we didn't record enterBackground
+        // we can't calculation bkgEvent duration so we ignore it.
+
+        backgroundTimesService.enterForeground()
+
+        val bkgTimes = backgroundTimesRepository.getBackgroundTimes()
+        assertThat(bkgTimes).isEmpty()
+        assertThat(bkgTimes.size).isEqualTo(0)
+
+        saveSingleBackgroundEventWorks()
+    }
+
+    @Test
+    fun pruneEventListUponReachingCapLimit() {
+
+        val capLimit = BackgroundTimesService.MAX_BKG_TIMES_ARRAY_SIZE
+
+        for (i in 1..capLimit + 20) {
+            backgroundTimesService.enterBackground()
+            backgroundTimesService.enterForeground()
+        }
+
+        val bkgTimes = backgroundTimesRepository.getBackgroundTimes()
+        assertThat(bkgTimes).isNotEmpty
+        // Due to an impl detail we're actually always keeping capLimit + 1 items (hehe)
+        assertThat(bkgTimes.size).isEqualTo(capLimit + 1)
+    }
+
+}
\ No newline at end of file
diff --git a/android/apolloui/src/main/java/io/muun/apollo/presentation/ui/base/SingleFragmentActivity.java b/android/apolloui/src/main/java/io/muun/apollo/presentation/ui/base/SingleFragmentActivity.java
index f7c0268c..ef1ba458 100644
--- a/android/apolloui/src/main/java/io/muun/apollo/presentation/ui/base/SingleFragmentActivity.java
+++ b/android/apolloui/src/main/java/io/muun/apollo/presentation/ui/base/SingleFragmentActivity.java
@@ -87,7 +87,10 @@ private boolean hasFragments() {
      * - Fragment#onAttach (so fragment is attached to activity, getActivity returns non null).
      */
     final void attachHeader() {
-        getHeader().attachToActivity(this);
+        final MuunHeader header = getHeader();
+        if (header != null) { // MuunHeader's optional for SingleFragment (see SingleActionFragment)
+            header.attachToActivity(this);
+        }
     }
 
     @Override
diff --git a/android/apolloui/src/main/java/io/muun/apollo/presentation/ui/settings/RecoveryCodeFragment.kt b/android/apolloui/src/main/java/io/muun/apollo/presentation/ui/settings/RecoveryCodeFragment.kt
index b8215424..e746dca0 100644
--- a/android/apolloui/src/main/java/io/muun/apollo/presentation/ui/settings/RecoveryCodeFragment.kt
+++ b/android/apolloui/src/main/java/io/muun/apollo/presentation/ui/settings/RecoveryCodeFragment.kt
@@ -61,7 +61,7 @@ class RecoveryCodeFragment : SingleFragment<RecoveryCodePresenter>(), RecoveryCo
         presenter.submitRecoveryCode(recoveryCodeBox.segmentInputsContent)
     }
 
-    override fun setRecoveryCodeError(error: UserFacingError) {
+    override fun setRecoveryCodeError(error: UserFacingError?) {
         recoveryCodeBox.setError(error)
     }