Hi Strix,
Thank you very much for your reply. I did try doing that. However, I encountered a problem. When I open the earliest backup, that version is not the version on the AnkiWeb I wanted to recover. That version is still the version after the error I made (as I have described in the original post). Are there any other ways that I can try to recover my decks? Please help me if possible. Thank you very much.
An