Based on the file you sent, I think something did go very wrong with it somehow! It's just a bunch of empty characters instead of the normal data, so there'd be no way to salvage any data that you did have unfortunately.
So that's almost definitely the cause, so if you delete that file it should be able to regenerate it properly and start working again! Any files you uploaded will still be in the folder in AppData (throws, impacts, decals, windups) but you'd need to upload them again.
The data file must've somehow gotten corrupted, but I have no way of knowing how that happened at the moment. I'll keep note of it and see if anything comes up, though!
Knowing this, I should be able to add something to automatically make a backup to load instead if it has issues loading the normal data file.