The answer is: Too many!

I’m playing on PS4, and I’ve had the game crash at least one time/map and session. On the “Crossing”, the game crashed 4 times in a single session. Now I’m doing “Deluge”, and the game has crashed 2 times before I’ve even made my way to the log kiosk.
What kind of joke is this? It would make sense if it was on PC with a lot of mods. Then I could sort of understand it. But on PS4? We can’t have mods, but the game is more likely to crash than to be stable an entire map.