How do I do a 'Clean Install' of a corrupt Vault Project?

I recently bought the Showcase Viewer on the Unreal Marketplace, and after trying to pump out a video with sequencer, the blueprint became corrupt. I have tried a reinstall of 4.19 and I have opened it on an older version with the same exact problem.

What if I want to start over with a clean project? Every time I open up a new ‘showcase viewer’ project from the vault I get an unresolved blueprint error.

…and when I go into the blueprints and press compile, UE4 immediately crashes.

If I sign in on a completely different computer and create the project from my vault, it runs perfect, then if it becomes corrupt, its like I can’t use it ever again on that computer.

Extremely frustrating, I’m just a student who’s trying to make a demo reel and hopefully get hired.