Why can't I restore my autosaved project?

So I had a few projects opened in Audacity but for some reason, after a windows update, my computer automatically restarted and all my autosaves were all deleted. I then used a program called EaseUS to restore my autosaved files but now whenever I try to restore them, Audacity keeps saying

“Audacity does not recognize the type of the file ‘C:\Users\Brandon\AppData\Roaming\audacity\AutoSave\NewProject New Project - 2020-02-15 16-07-52 N-4.autosave’. Try installing FFmpeg. For uncompressed files, also try File > Import > Raw Data.”

Does anyone know what’s going on?

I’m surprised by that, but:

  1. Rebooting is likely to delete temporary files
  2. Force quitting Audacity can have unpredictable results - if Audacity is in the middle of writing data at the exact moment that it is shut down, then that data could be corrupted.
  3. The Audacity project file is updated after audio data has been written to disk. If Audacity is shut down after writing audio data but before the .aup file has been updated, then the .aup file (the project file) will point to the wrong data.

If you’re cooking a soufflé in an electric oven and the power goes off during cooking, then the soufflé will be ruined. The same can happen when powering down the computer while an app is writing data.

EaseUS can be a very useful app for restoring data, but in my experience it does not handle Audacity data files very well. I have not found any “rescue” program that can reliably restore Audacity data files unless they can simply be restored from the recycle bin.

Neither of those are likely to work. Those suggestions assume that you are attempting to import valid audio data. The “rescued” files are probably not valid audio data. If they were valid audio data, then Audacity would have been able to open them. Most likely that the “restored” files are corrupt junk.