Do the developers even read this forum?
On the steam forum there are several answers from the devs....none here....
Apologies for being slow to respond here. I have had a couple of very brief looks across the GOG forums here over the past two days, but didn't spot this thread until after one of you lovely people made a thread on the Steam forums (thanks so much for helping to bring that to our attention - it's been a very, very busy couple of days).
We don't yet have a solid handle on what the cause is here, but we would *love* to get our hands on a copy of your game logs that include the crash (logs get overwritten each time the game starts).
On Linux, the log can be found in: ~/.config/unity3d/Defiant\ Development/Hand\ of\ Fate 2/Player.log
On Windows: C:\Users\<username>\AppData\LocalLow\Defiant Development\Hand of Fate 2\output_log.txt
On Mac, press Command+Shift+G in Finder to bring up the location dialog and enter the following path, looking for Player.log: ~/Library/Logs/Unity/
You can pop those up to pastebin or whatever and link them here, and I'll try to keep an eye out, or alternatively, you can send them through to firstname.lastname@example.org with "GOG crash on exit" as the subject.
Sorry for the inconvenience and for the lack of communication here!