I suppose that the game is trying to save a value (-1) that does not exist and that's why its crashing?
The -1 breaks the audio object. When you save locally, it tries to grab information from that object differently from the non-local way. I'm not sure exactly why this causes a crash, but it does and once RTB approves the fixes, it should be safe to use.
I'm sorry in advance for any saves I've destroyed, although, how situational it all is, is unlikely there were many.