The reason it’s seemingly stuck is it’s recompiling shaders (not your materials) and that can take a really long time sometimes. Letting it be a couple of hours should fix it, if not, force the process to end with task manager, locate the .txt with your project settings and disable global clip plane. Restart the editor and if it opens your project that means everything is working (to make sure it was stuck because of global clip plane specifically), after which you can re-enable it and try again.