diff --git a/f7/app.py b/f7/app.py
index 9c8d238..28238b3 100644
--- a/f7/app.py
+++ b/f7/app.py
@@ -99,7 +99,7 @@ class _App:
             if msgid == _IM_DoneCallback:
                 self._IMDoneCallback(callback)
         except Exception as e:
-            f7.udplog.error('_dispatchIMMsg ' + str(e))
+            f7.udplog.error('_dispatchIMMsg %d %s' % (msgid, str(e)))
 
     def _addIMMsg(self, msgid, callback):
         self._immsgLock.acquire()
@@ -112,8 +112,12 @@ class _App:
         callback()
 
     def createAsyncTask(self, done_callback, func, *args):
+        assert self._listened
         def thread_func(args):
-            func(args)
+            try:
+                func(args)
+            except Exception as e:
+                f7.udplog.error('_dispatchIMMsg ' + str(e))
             if done_callback:
                 self._addIMMsg(_IM_DoneCallback, done_callback)
         thread = threading.Thread(target = thread_func, args = args)