Hmm. I apologise, it obviously shouldn't do that, both throwing a null pointer and then ruining it the quicksave.
I'll confess saving and loading has been an utter pain. We spent a month wrestling with different libraries, but for some reason our code breaks the Unity engine itself when trying to save. There's no error message or online documentation, so it's currently the best we can manage to get somewhat working.
I'll see about expanding the number of save slots, and making it create backups of save files before loading, which should hopefully reduce the pain this causes.
Regarding the game itself, I've got less time to work on it than I did before, and am implementing features people ask for (currently agents) when I find time. Hopefully in time this version will be better in every way than the previous one, but I guess that may be subjective.
We'll do more playtesting to try to track down the nullpointer, and put a fix to that too.
Thanks for your feedback, though.