hi, if you can check the security settings of that folder, you might need to add yourself to each nested folder.
have you tried to make an extra account with admin priviledges, and to then log on as that user, and to try to give yourself permissions again?
failing that, if you can actually see your data, and if its not too big, can you at least try to copy it and paste it somewhere to verify, to at least be able to access it again meanwhile?
alternatively - if you are still using the system and havent done much else in terms of operations, does “undo move” move it back out? (check the undo its worth a shot)