diff --git a/tools/chatgui-android/app/src/main/java/com/utun/chat/data/AvatarRepository.kt b/tools/chatgui-android/app/src/main/java/com/utun/chat/data/AvatarRepository.kt
index d0f37657..3b3a4241 100644
--- a/tools/chatgui-android/app/src/main/java/com/utun/chat/data/AvatarRepository.kt
+++ b/tools/chatgui-android/app/src/main/java/com/utun/chat/data/AvatarRepository.kt
@@ -27,6 +27,7 @@ class AvatarRepository(context: Context) {
     private val app = context.applicationContext
     private val scope = CoroutineScope(SupervisorJob() + Dispatchers.Main.immediate)
     private val transfers = Semaphore(2)
+    private val preparations = Semaphore(2)
     private val ids = AtomicLong(System.nanoTime())
     private var generation = 0L
     private var account = 0L
@@ -73,7 +74,7 @@ class AvatarRepository(context: Context) {
     }
 
     private data class Pending(val type: Int, val group: Long, val server: Long, val owner: Long,
-                               val command: Int, val result: CompletableDeferred<ByteArray>)
+                               val command: Int, val result: CompletableDeferred<ByteArray>, var cancelled: Boolean = false)
     private fun log(level: String, message: String) = LogManager.addLog(level, "Avatar", message)
     private fun changed() { _revision.value++ }
     private fun alive(epoch: Long) { if (generation != epoch || account == 0L) throw CancellationException("avatar session changed") }
@@ -157,11 +158,15 @@ class AvatarRepository(context: Context) {
     private fun reset() {
         log("INFO", "Reset account=${AvatarProtocol.hex(account)} pending=${pending.size} cacheBytes=${cache.size()}")
         generation++
+        pending.forEach { (id, p) ->
+            if (p.type in 49..50 && NativeLib.isReady()) { p.cancelled = true; NativeLib.cancelAvatar(id) }
+        }
         scope.coroutineContext.cancelChildren()
         pending.clear(); loads.clear(); replications.clear(); dirtyGroups.clear(); memberRequests.clear(); editTokens.clear()
         account = 0; defaultAvatar = null; cache.evictAll()
         _members.value = emptyMap(); _groups.value = emptyMap(); _edits.value = emptyMap(); changed()
     }
+    fun stop() { reset() }
     private fun start() {
         val uid = NativeLib.getMyNodeId()
         if (uid == 0L || uid == account) return
@@ -188,7 +193,8 @@ class AvatarRepository(context: Context) {
                                 enqueue: (Long, Long) -> Boolean): ByteArray {
         val id = ids.incrementAndGet(); val gid = AvatarProtocol.node(group)
         val result = CompletableDeferred<ByteArray>()
-        pending[id] = Pending(type, gid, server, owner, command, result)
+        val operation = Pending(type, gid, server, owner, command, result)
+        pending[id] = operation
         var complete = false
         try {
             if (!enqueue(id, gid)) throw IOException("native enqueue failed id=$id type=$type group=$group")
@@ -197,7 +203,7 @@ class AvatarRepository(context: Context) {
             return data
         } finally {
             pending.remove(id)
-            if (!complete && type in 49..50 && NativeLib.isReady()) NativeLib.cancelAvatar(id)
+            if (!complete && !operation.cancelled && type in 49..50 && NativeLib.isReady()) NativeLib.cancelAvatar(id)
         }
     }
 
@@ -431,7 +437,7 @@ class AvatarRepository(context: Context) {
     }
 
     /** Чтение URI, EXIF, crop и кодирование выполняются вне UI и потока ядра. */
-    private suspend fun prepare(uri: Uri, group: Boolean): ByteArray = withContext(Dispatchers.IO) {
+    private suspend fun prepare(uri: Uri, group: Boolean): ByteArray = preparations.withPermit { withContext(Dispatchers.IO) {
         val temp = File.createTempFile("avatar-source-", ".image", app.cacheDir)
         try {
             app.contentResolver.openInputStream(uri)?.use { input ->
@@ -445,7 +451,7 @@ class AvatarRepository(context: Context) {
                 }
             } ?: throw IOException("cannot read selected image")
             val (w, h) = PhotoUtil.orientedDimensions(temp.path)
-            require(w > 0 && h > 0 && w.toLong() * h <= 100_000_000) { "invalid source dimensions $w x $h" }
+            require(w > 0 && h > 0 && w.toLong() * h <= 16L * 1024 * 1024) { "invalid source dimensions $w x $h" }
             var sample = 1
             while (maxOf(w, h) / sample > 1024) sample *= 2
             val decoded = PhotoUtil.decodeOriented(temp.path, sample) ?: throw IOException("source decode failed")
@@ -468,5 +474,5 @@ class AvatarRepository(context: Context) {
                 decoded.recycle()
             }
         } finally { if (!temp.delete()) log("WARN", "Cannot delete source temp=$temp") }
-    }
+    } }
 }
diff --git a/tools/chatgui-android/app/src/main/java/com/utun/chat/data/NativeLib.kt b/tools/chatgui-android/app/src/main/java/com/utun/chat/data/NativeLib.kt
index 3e708eb0..78418ad4 100644
--- a/tools/chatgui-android/app/src/main/java/com/utun/chat/data/NativeLib.kt
+++ b/tools/chatgui-android/app/src/main/java/com/utun/chat/data/NativeLib.kt
@@ -42,7 +42,7 @@ object NativeLib {
     }
 
     fun stop() {
-        runBlocking(Dispatchers.Main.immediate) { CallController.reset() }
+        runBlocking(Dispatchers.Main.immediate) { CallController.reset(); ChatApplication.instance.avatars.stop() }
         if (!isReady()) return
         nativeStop()
     }
@@ -54,12 +54,12 @@ object NativeLib {
     }
 
     fun destroy() {
-        runBlocking(Dispatchers.Main.immediate) { CallController.reset() }
+        runBlocking(Dispatchers.Main.immediate) { CallController.reset(); ChatApplication.instance.avatars.stop() }
         nativeDestroy()
     }
 
     fun restart(dbPath: String, controlPort: Int, configText: String): Boolean {
-        runBlocking(Dispatchers.Main.immediate) { CallController.reset() }
+        runBlocking(Dispatchers.Main.immediate) { CallController.reset(); ChatApplication.instance.avatars.stop() }
         return nativeRestart(configText)
     }
 
diff --git a/tools/chatgui-android/app/src/main/java/com/utun/chat/ui/components/AvatarEditors.kt b/tools/chatgui-android/app/src/main/java/com/utun/chat/ui/components/AvatarEditors.kt
index dccfc5a2..9c8ef612 100644
--- a/tools/chatgui-android/app/src/main/java/com/utun/chat/ui/components/AvatarEditors.kt
+++ b/tools/chatgui-android/app/src/main/java/com/utun/chat/ui/components/AvatarEditors.kt
@@ -62,6 +62,7 @@ fun GroupPropertiesDialog(channel: Channel, onDismiss: () -> Unit) {
                     Text(stringResource(R.string.sound), modifier = Modifier.weight(1f))
                     Switch(checked = soundOn, onCheckedChange = {
                         soundOn = it; NotificationSound.setMuted(channel.id, !it)
+                        NativeLib.setSoundOnMessage(channel.id, it)
                         scope.launch { ChatApplication.instance.configProvider.setChannelMuted(channel.id, !it) }
                     })
                 }