ahh don't worry about it collections without .format was old database system and it has been replaced by collections.lowdb soo do not worry about unformated file let them be, just delete collections then make every file that it said does not exist (just delete collections db not others)
Would it be possible to store download progress and resume it later? Kind of like how the repair function works. I think that might fix any hangup issues without canceling a download and retrying it a million times. Other than that, you have a nice app going here :)
