I’ve been using Unreal for the past two years, and slowly settling back into Unity.
I’m getting this starting up my project, which has been fine for a couple of weeks. Finding an absolute torrent of errors though. I don’t even know what this one means … ? There’s no other process open, and I’m not sure what these logs are doing to make it actually crash when you press force quit.
Have you put the project in something like Google Drive or Dropbox? Because that’s a bad idea and you should be using a standard form of version control like Git.
Alternatively something else might have tried to use the file, like bad antivirus software.
Torrents of errors always warrant deleting the Library folder. With project closed of course.
Also note that you are using a very outdated, unsupported editor version (2020.2). Please upgrade at least to 2020.3, better 2021.3 and while you are at it go all the way up to 2022.3. For a solo developer there is absolutely no point in version locking yourself unless you are getting very close to release.
Btw in ten years working intensively with Unity I have not seen this error before. I wager this is more likely an issue with the system (ie said Antivirus or cloud sync or a backup software) rather than a particular Unity problem. Make sure to exclude the project from antivirus scans, and make sure any backups don‘t run while the project is open - those backups surely will capture some in-between state that would leave the backup project incomplete or broken.