Quickly looking at some past comments, there are SOME people who have experienced this too. Help the dev out first by providing as much information about it first.
- What platform are you playing on?
- Was the save file originally stable in a previous version? (did you bring an old save file to a new version of the game?)
- What primary story events did you play?
- Was there a specific event you finished and then exited?
Any information you can give with make the Devs life a little easier.