I am having an issue where when i go to create any asset within unity (like a C# script or a shader or a material or even a folder) it does nothing and gives me a NullReferenceException error. Now I can create assets in whole new project just fine and i can import assets from another project just fine but creating things from scratch in this project just gives me that error.
I would abandon that project and copy your stuff to a whole new one. I’ve had problems where my assets ‘double’, that is, they show up twice each (not all of them!) in the Project, but only one is legit, the other gives error. Just create new project, copy assets over. You may want to Export Package on the good stuff, then Import them in the new project to reconnect everything.