Hmm, I don't know how to fix it some people fix this problem but it's in many ways or they did not tell how.. What you can try: Manual install the default.fos by placing the default.fos in the mygame save folder yourself if you did it this way at the first place try it the other way around open the vaultmp client select your server and click Synchronize.

If this did not work, download vaultmp again and try it the same way also try to reconnect many times.