Re: Error during ask-user-about-lock

[Richard Stallman]

    Visit a file that you have modified in another emacs session.  Emacs asks
    what you want to do about the lock.  Hit "?" to popup the *Help* window in a
    new frame.  After the frame has appeared, I get an immediate:

    Debugger entered--Lisp error: (error "Non-character input-event")
      read-char()
      byte-code(...)

Can you find out what Lisp object the event is?
That should make the cause clear.