I'm not sure it has anything to do with the force-quitting, but let's look into it. Is this just on tapping the menu entry, or are you selecting something inside of the crossword page?
Just the menu. Never got as far as opening the crossword page.
I have no problem with the custom crossword in my schedule, just the crossword page. It may be relevant that it was last open to an N4 kanji puzzle from 2020. August, I think.
No, it’s still broken. Force-quitting is not necessary to see the error messages. I can get the same behavior by just moving to another page while waiting for the crossword page to open.