I found a solution on Reddit which worked for me.
Log into the game, disconnect from the internet, reconnect, go back to Unbound and make sure it's in offline mode, and then click to go back online. It should reinstall all the inventory correctly this time. At least, that's how I fixed it. Got the issue a few days ago and that's how it stopped.
@RabitShiny Are you on console or PC? I'm on PC.
Your post got me thinking - is it possible to use another user's save file? I had assumed not as the file would somehow be attached to your username.
If possible, that would go a long way to alleviating people's woes over corrupted and lost save files.
It wouldn't be an ideal "fix" but would go a long way to helping people nonetheless.
Yes, I'm on PC too, Steam to be exact, and well I had to start from scratch, fortunately my favorite cars are not difficult to unlock except for the Dodge Viper, and to do the activities and collectibles again 😭
@RabitShiny That sucks - hopefully you weren't too far into game. At lvl250 and 800H, no way I could deal with starting again.
I'm trying to figure out if it's possible to use another user's save file. Some users seem to suggest yes whilst others no. If it were possible, that would go some way to helping "fix" this problem.
In any case, I backup my save file DAILY now. Just copy and paste into another folder (not overwriting previous version).
If NFSU wasn't as fun as it was, I would've moved on by now. Oh the woes!
