Having this issue now myself.
I can't load any of the saves my friends and I have played together. As soon as it begins loading, it crashes to desktop immediately.
We are playing with a handful of mods, but strangely enough, I can start a new game with all of those mods, create a save, and reload that save without issue. But it looks like all our saves are corrupted or something?
About to shoot an e-mail off to that address Raze suggested as well!
Any other suggestions?
