I'm really sorry about that, a similar bug has been reported to me not long ago and fixing it is now my priority. It seems to be a rare bug that only occurs for a few people, though the other person didn't have the screen freeze at the end of fights but at other points in the game. The game still ran fine otherwise like you described.
This person seemed to have some luck mitigating that bug by pressing Ctrl + Esc, minimizing then clicking back into the game, but of course that's not a good enough fix and might not even work for everyone.
As for debug mode, you need to still be holding Enter and Left shift when pressing F2. Is that what you did?
If you can, sending me relevant screenshots (before the freeze, after the freeze, anything else that comes to mind) at nosebecc@gmail.com might help me figure out the bug!
In any case, I apologize once again. I'll do my best to have this fixed ASAP!