All content and config files are there, but the project opens as if it was blank. Entire project is "gone".

[stuck_compiling]

Hey! Yes, that’s the case. I managed to “fix” this by opening an old backup of the project, then deleting everything inside the content folder. Then, while the project is running, I copy-pasted the “lost” content files, and they were immediately recognised by Unreal. This seems to have worked with no negative side-effects.