I also experienced a similar issue once one of my blueprints got corrupted due to it’s parent C++ class not being compiled properly before the editor could launch. What caused this might be different in your case, but you should be able to fix it by deleting all the VS related folders (the .vs folder, the Source folder and the .sln file) and regenerating them by creating a new C++ class in your project, if your issue is C++ related. If not, you can also try deleting the Binaries and Intermediate folders and regenerating them again by building your project from VS.
Disclaimer: Always make sure to back up your project before editing the project folder!!!