diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/events/model/Event.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/events/model/Event.kt
index 7aea73233d..bc6885eddc 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/events/model/Event.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/events/model/Event.kt
@@ -134,7 +134,7 @@ data class Event(
     }
 
     fun toContentStringWithIndent(): String {
-        val contentMap = toContent()?.toMutableMap() ?: HashMap()
+        val contentMap = toContent().toMutableMap()
         return JSONObject(contentMap).toString(4)
     }
 
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/algorithms/megolm/MXMegolmDecryption.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/algorithms/megolm/MXMegolmDecryption.kt
index 6ffaf776b2..0230141e1b 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/algorithms/megolm/MXMegolmDecryption.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/algorithms/megolm/MXMegolmDecryption.kt
@@ -244,13 +244,6 @@ internal class MXMegolmDecryption(private val userId: String,
             keysClaimed = event.getKeysClaimed().toMutableMap()
         }
 
-        if (roomKeyContent.sessionId == null
-                || roomKeyContent.sessionKey == null
-                || roomKeyContent.roomId == null) {
-            Timber.e("## invalid roomKeyContent")
-            return
-        }
-
         val added = olmDevice.addInboundGroupSession(roomKeyContent.sessionId,
                 roomKeyContent.sessionKey,
                 roomKeyContent.roomId,
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/algorithms/olm/MXOlmEncryption.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/algorithms/olm/MXOlmEncryption.kt
index b6d1b98546..1c275940af 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/algorithms/olm/MXOlmEncryption.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/algorithms/olm/MXOlmEncryption.kt
@@ -66,7 +66,7 @@ internal class MXOlmEncryption(
         )
 
         messageEncrypter.encryptMessage(messageMap, deviceInfos)
-        return messageMap.toContent()!!
+        return messageMap.toContent()
     }
 
     /**
diff --git a/vector/src/main/java/im/vector/riotx/core/utils/FileUtils.kt b/vector/src/main/java/im/vector/riotx/core/utils/FileUtils.kt
index 0009fd46f9..1a19b49872 100644
--- a/vector/src/main/java/im/vector/riotx/core/utils/FileUtils.kt
+++ b/vector/src/main/java/im/vector/riotx/core/utils/FileUtils.kt
@@ -126,7 +126,7 @@ fun getFileExtension(fileUri: String): String? {
  * Size
  * ========================================================================================== */
 
-fun getSizeOfFiles(context: Context, root: File): Int {
+fun getSizeOfFiles(root: File): Int {
     return root.walkTopDown()
             .onEnter {
                 Timber.v("Get size of ${it.absolutePath}")
diff --git a/vector/src/main/java/im/vector/riotx/features/settings/VectorSettingsGeneralFragment.kt b/vector/src/main/java/im/vector/riotx/features/settings/VectorSettingsGeneralFragment.kt
index 7ad7ba5ce1..331b6e935a 100644
--- a/vector/src/main/java/im/vector/riotx/features/settings/VectorSettingsGeneralFragment.kt
+++ b/vector/src/main/java/im/vector/riotx/features/settings/VectorSettingsGeneralFragment.kt
@@ -185,8 +185,7 @@ class VectorSettingsGeneralFragment : VectorSettingsBaseFragment() {
 
         // clear medias cache
         findPreference<VectorPreference>(VectorPreferences.SETTINGS_CLEAR_MEDIA_CACHE_PREFERENCE_KEY)!!.let {
-            val size = getSizeOfFiles(requireContext(),
-                    File(requireContext().cacheDir, DiskCache.Factory.DEFAULT_DISK_CACHE_DIR))
+            val size = getSizeOfFiles(File(requireContext().cacheDir, DiskCache.Factory.DEFAULT_DISK_CACHE_DIR))
 
             it.summary = TextUtils.formatFileSize(requireContext(), size.toLong())
 
@@ -203,8 +202,7 @@ class VectorSettingsGeneralFragment : VectorSettingsBaseFragment() {
                         // On BG thread
                         Glide.get(requireContext()).clearDiskCache()
 
-                        newSize = getSizeOfFiles(requireContext(),
-                                File(requireContext().cacheDir, DiskCache.Factory.DEFAULT_DISK_CACHE_DIR))
+                        newSize = getSizeOfFiles(File(requireContext().cacheDir, DiskCache.Factory.DEFAULT_DISK_CACHE_DIR))
                     }
 
                     it.summary = TextUtils.formatFileSize(requireContext(), newSize.toLong())