Hmm, I haven't been able to think of anything that could be the culprit. I could potentially create a special build for you that generates a log and maybe that would give some insight. It will take a few days to get it ready (my time is very short right now), and I totally understand if you aren't interested or can't (I don't like having a player essentially debugging for me)
Do it when you have time. I'm curious about it but I'm not desperate to play the game RIGHT NOW.
Ok, there should be a new build available named 'Walking Tourist x64 Logged'
It will generate a file named <number>.log when run (<number> will change every time it is run). Its contents won't be terribly useful to you, but may help me pinpoint what is failing. You can either post the last handful of lines in the file here, or email the whole file to email@example.com.
Also it will run super slow so it may take longer to hit the crash. E.g. it normally starts instantly, but now takes a good 5 - 10 seconds to hit the splash screen for me. There is also a slim, but unlikely chance I fixed the issue (this build includes an engine update; however no fixes should be related to the issue you are seeing).