dissapearance of uploaded files

Everytime I rename the file or compile the files into a different folder, all my uploaded files in that folder would dissapear. I can’t access it anymore when i click into the folder. But i can still use the flashcards for those individual files. It would just compile all my flashcards into one big flashcard group. How do I retrive back my files? this is wasting my time to reupload everything again and also cost me my file upload count per month.