I’ve had the same problem and what I’ve made is delete all *.meta files in “Assets” folder in my project. Unity had to import all assets again and the project still works good
You can also delete the last added script from assets and try to import it again. Maybe it would help.
My project crashed once and cannot be opened again. What worked for me was to open that project on different computer, export the package and the re-import the package in the computer that was crashed.
OK Guys, What is happening is after a crash, the scripts that have caused your crash or contributed to it can’t compile upon restart. follow these step to fix it.
Make a backup
remove your scripts folder
open your project.
re-import your scripts folder.
apply the scripts back to where they were.
save project and scene
If that doesn’t work: reinstall unity then follow steps.