I get same error too. I use EmacsW32 (on MS Windows). After any error screen does not split on 2 frames. Debugger is open new full-screen frame. After close it I have:
it would be helpful if people with this error could enable "enter debugger on error" in emacs and paste the emacs backtrace, and also send the output of "emacs --version".
i'm lost without being able to reproduce it.