diff --git a/tools/chatgui-android/app/src/main/java/com/utun/chat/data/AvatarProtocol.kt b/tools/chatgui-android/app/src/main/java/com/utun/chat/data/AvatarProtocol.kt
index 8cbc27da..94bdaa0c 100644
--- a/tools/chatgui-android/app/src/main/java/com/utun/chat/data/AvatarProtocol.kt
+++ b/tools/chatgui-android/app/src/main/java/com/utun/chat/data/AvatarProtocol.kt
@@ -9,6 +9,8 @@ object AvatarProtocol {
     const val MAX_GROUP = 16 * 1024
     private val filePattern = Regex("[0-9a-f]{64}\\.png")
     fun validFile(file: String): Boolean = filePattern.matches(file)
+    // channel_id в БД/событиях — десятичный u64; avatar_server в userinfo — hex.
+    fun groupId(id: String): Long = id.toULongOrNull(10)?.toLong() ?: 0
     fun node(id: String): Long = id.toULongOrNull(16)?.toLong() ?: 0
     fun hex(id: Long): String = id.toULong().toString(16).padStart(16, '0')
     fun hash(bytes: ByteArray): String = bytes.joinToString("") { "%02x".format(it.toInt() and 255) }
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 07ff10ab..2c3fad86 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
@@ -182,7 +182,10 @@ class AvatarRepository(context: Context) {
     }
     private fun requestMembers(group: String) {
         if (account == 0L) start()
-        if (account == 0L || AvatarProtocol.node(group) == 0L) return
+        if (account == 0L) return
+        if (AvatarProtocol.groupId(group) == 0L) {
+            log("WARN", "Member snapshot: invalid decimal channel_id=$group"); return
+        }
         val now = android.os.SystemClock.elapsedRealtime()
         if (now - (memberRequests[group] ?: -5000) < 5000) return
         memberRequests[group] = now
@@ -191,12 +194,14 @@ class AvatarRepository(context: Context) {
 
     private suspend fun request(type: Int, group: String, server: Long = 0, owner: Long = 0, command: Int = 0,
                                 enqueue: (Long, Long) -> Boolean): ByteArray {
-        val id = ids.incrementAndGet(); val gid = AvatarProtocol.node(group)
+        val id = ids.incrementAndGet(); val gid = AvatarProtocol.groupId(group)
+        require(gid != 0L) { "invalid decimal channel_id=$group" }
         val result = CompletableDeferred<ByteArray>()
         val operation = Pending(type, gid, server, owner, command, result)
         pending[id] = operation
         var complete = false
         try {
+            log("DEBUG", "Request id=$id type=$type group=$group parsedGroup=${gid.toULong()} server=${AvatarProtocol.hex(server)}")
             if (!enqueue(id, gid)) throw IOException("native enqueue failed id=$id type=$type group=$group")
             val data = withTimeout(60_000) { result.await() }
             complete = true
@@ -209,7 +214,10 @@ class AvatarRepository(context: Context) {
 
     fun ensureGroup(group: String, force: Boolean = false) {
         if (account == 0L) start()
-        if (account == 0L || AvatarProtocol.node(group) == 0L) return
+        if (account == 0L) return
+        if (AvatarProtocol.groupId(group) == 0L) {
+            log("WARN", "Group snapshot: invalid decimal channel_id=$group"); return
+        }
         if ("group:$group" in loads) { if (force) dirtyGroups.add(group); return }
         val current = _groups.value[group]
         if (!force && current != null && !current.error &&
diff --git a/tools/chatgui-android/jni_bridge/android_jni_bridge.c b/tools/chatgui-android/jni_bridge/android_jni_bridge.c
index 26a05699..384cc683 100644
--- a/tools/chatgui-android/jni_bridge/android_jni_bridge.c
+++ b/tools/chatgui-android/jni_bridge/android_jni_bridge.c
@@ -2684,8 +2684,8 @@ static void android_avatar_snapshot(void* arg) {
     struct group_avatar_record record;
     memset(&record, 0, sizeof(record));
     int failed = group_avatar_get(req->inst, req->group, &record) < 0;
-    char channel[17]; uint8_t key[32];
-    snprintf(channel, sizeof(channel), "%016llx", (unsigned long long)req->group);
+    char channel[32]; uint8_t key[32];
+    snprintf(channel, sizeof(channel), "%llu", (unsigned long long)req->group);
     int can_edit = topo_node_sqlite_channel_get_priv(chat_core_get_db(req->inst), channel, key) == 0;
     memset(key, 0, sizeof(key));
     if (failed) DEBUG_WARN(DEBUG_CATEGORY_CHAT, "Android avatar: snapshot failed group=%s id=%llu", channel,