after upgrade to 2v11: App Loader no longer working

I might have found a solution:

• at first, connect using the Web IDE
  
• then, in another window, open the App Loader and connect (the Web IDE will show you any responses from the watch)
  
• upgrade any outdated apps (e.g., Settings, Bootloader etc.) and/or delete an old/install a new application
  
  

From then on, everything seems to work fine again - but don't ask me why!