This discussion may contain spoilers!
I played my game without any problems up to chapter five
Up to the moment where Clementine spots her parents
Then after choosing one of the options on the screen, the game crashed.
After that, all the progress from Chapter 5 simply vanished, whenever I chose to start chapter 5, it said that none of my choices would be carried over (as if I hadn't played through Ep.4. However, whenever I tried to start from ep.4, it'd say that I'd be rewinding the game, and when I chose yes, the game got stuck on a black screen.
I searched around, and I read that the save was useless now, so I deleted it and started over. Then, when I was about to start to play chapter 2, it asked me again if I wanted to rewind the game and it got stuck on the same black screen.
I'm playing on a Mac, the Steam version of the game.