I was doing yesterday's Wall Street Journal puzzle. I'd done a little, accidentally trashed the .puz file from the Desktop, then saved again after doing some more. I got the alert about the file being in the trash and saved it as a new file (same old name) on the Desktop. And a minute later it crashed.
Thanks for reporting this. I tried to follow the same steps and wasn't able to reproduce the crash, but I will keep trying with some different puzzles.
I took a stab at reproducing it myself and couldn't. The crash might have nothing to do with how and when I saved the puzzle, that's just the only unusual thing I could point to.