fix

iOSClient/AppDelegate.m

@@ -218,7 +218,9 @@
         [self.activeDetail.richDocument grabFocus];
     }
     
-    [[NSNotificationCenter defaultCenter] postNotificationOnMainThreadName:@"applicationWillEnterForeground" object:nil];
+    dispatch_async(dispatch_get_main_queue(), ^{
+        [[NSNotificationCenter defaultCenter] postNotificationOnMainThreadName:@"applicationWillEnterForeground" object:nil];
+    });
 }
 
 //