Might hade deleted a critical file

I migrated my games lvls to a different project so it would be smaller and I was deleting the unused things and then ue5 crashed and now no instancee of 5.3 whatsoever, dosent matter the project wont open. Please help

Restore from backups.

Look into git or github, get account there use github for backups. Or zip your projects and copy/move zips to another harddrive.