Can not open saves

[rj237123]

I do not think I installed a patch. This ordeal started while I was playing the game. I played for a few hours and saved a few times in-between.
One time when I tried to save, it didn’t let me so I kept playing and then when I died, that error came up. I tried playing again but I keep getting that error every time. I restarted my computer and still get it.