Ok, thanks both of you for responding, and thanks for submitting that bug report — I see both your responses on Discord as well. It sounds like this is all connected, the prolonged saving and the file corruption. What's weird is the corruption of the saving seems to have been within a limited time period for me. The auto save and and the manual save at the time both got corrupted but the next day when
dop2000 asked me to try opening a working version and saving then I was able to open the newly saved file. I just tried again and confirmed that I can save and re-open working files. Why would this only affect that period, at least a 20 min period, where it would corrupt both the auto save and the manual save? Very strange.