I've only noticed this when I've been recently playing on Windowed Fullscreen.

What happens is that the game all of a sudden turns black, but I can still hear the sound going on in the background. I cannot recall if it only happened when tabbed out, but it did at least once when I was tabbed out. I highly doubt this is zone specific, because it once happened when I was tabbed out just chilling in the first city, and it also happened right after I had killed the boss Edric (?). I was able to hear the cinematic in the background but that was about it.

When this black screen happens, I am unable to ALT F4 out of the game, I cannot tab out and then successfully close it via the task bar. I have to force shut it down via the task manager. The first time this happened I also had to restart Steam, because it insisted that the game was playing after I closed it.

This first crash also made me lose access to a rare vendor in a Bounty instance that sold a 5 star quality weapon 🙃