christoph based on what you describe, it seems that there is a crash inside of one of native libraries that I use in my app, something like access violation. Otherwise there would be some kind of error message at least.
Based on the crash dump analysis on Windows, latest versions app only crash this way if memory chunk fails to allocate. However, that might not be the case here, as you indicate that memory is 50% free all the time.
Another frequent reason for not working on Linux - some incompatibility with system libraries, though I doubt that is the case here, as app would just not start at all.
Let me be 100% honest with you here. Unless this is some mainstream distro like Ubuntu, there is no chance I will be able to allocate resources for reproducing this issue in my lab and debug it. There are literally millions of different unique HW+OS combinations, so resources and effort spent for fixing issue on one of them will have zero effect on other users with different unique combination. So I just can’t afford it, I’m sorry. All I can do in situations like that is to say how sorry I am, assume that this is just another combination that my software does not support, and move on. And refund the customer of course.
Every time I feel very bad that I can’t help, but indeed there is not much I can do apart from general advice like check the tire pressure, wipe the windshield and make sure you are not on the parking brake. Most of the time users have much more expertise in their system than I can offer, and once in a while they can find the solutions themselves. I guess this is the way. There will always be systems on which my app will not work, probably plenty of them. Not much I can do about it.
Probably you saw this popular video where Linus Torvalds talks why it is a nightmare to make software for Linux, even for himself. If not, please check it out, it explains a lot: