My unreal engine is breaking so annoyed...

No its never happened before and not happened since I literally just saved my project closed it down and day later opened it up again and blueprints couldnt be opened but are still in my project folder… Just not recognised so I’ve just finished remaking them :\
Yes I tried the back up files the latest ones said the same error so had to use older map file and no I don’t use source control but i really should start