Challenge Save not showing now

[Warsaw]

Hi, I was playing the Whiteout Challenge and when I went into one of the houses to save (near the garage) it was starting to have a slowdown and once the icon was done spinning to save all the screen went to was a black screen.  Audio however was still present as I was in the house.  I figured this was just an error or something so after I waited a few minutes for the game to come to with nothing happening I exited the game and tried reloading it up.  When I went to go to the challenges again it showed that I have no current game save?  I did a google search and didn't really find much other than to verify my game cache integrity (which I did).  I'm hoping my game save is not corrupt or can be brought back as I had just about everything I needed to start to finish the challenge.  

Any suggestions or ideas on what I should do to bring back the save?  Additionally let me know if I need to provide any logs or anything of that matter.

Thanks