Is any of this stuff backed up? Do you have all original work or recordings saved as WAV (Microsoft) 16-bit sound files? You may need to get them out of storage and start the production(s) again. If a crash happens in the middle of editing, that’s usually the end of the world, even if it seems relatively minor.
I can make this worse. A crash or missing block files can invite more crashes or instability. So even if you have a localized single or two or three missing block files, you should not try to edit around them. Make backup Projects and WAV files of the work immediately—if you can. It’s possible for a large production to run out of machine or hard drive. Audacity creates EDIT > UNDO by carefully making copies of The Whole Show. So if you have a production with a lot of edits, the “data show” is going to be a lot larger than you think.
It’s highly recommended that you Export WAV files of all original performances or recordings, errors and all, before you do anything to them. It’s a New User Error to announce some work (for example) and then dive right into editing without making clean copies first. In extreme cases, Audacity may damage the final edit master after days of work and it sends the editor all the way back to performing at the microphone.
Koz