I've had it crash while fighting The Keeper & the last boss. After several tries is when it happens. Both the Denuvo+Steam & GOG versions have the issue.

I had the final boss down to 20%, then got hit with the worst, cheapest 1-hit kill attack of all time: A GAME CRASH. Maybe there is a memory leak in the game?

Running LOTF as an Admin didn't seem to help.

I tried turning the Nvidia GPU power managment mode to "Optimal perfomance" (it was on Prefer Maximum Performance when I had that crashing problem). This last time, I was able to get the end boss & finish the game. Before this I also turned on the Windows 7 compatibility mode for the exe as well.

https://steamcommunity.com/app/265300/discussions/0/616199736995755488/
This is a post by Steam user Wolf Pacifier about the crashing issues.

Started an NG+ & the crashing returned after awhile. I tried the Compatibility Troubleshooter on it.
The CT said LOTF was an incompatible program, so I figured I'd go with its recommended fixes. It applied Win8 compatibility mode. No more crashing after that so far. Hopefully this nailed it.

So, to recap: LOTF GOG + Win 8 compatibility mode = no crashes anymore?

I played the game from beginning to end with no crashes on Windows 10 (AMD Build).

Start to finish (~18 h), three crashes. Once just as I was running towards the checkpoint to save the previous ~40 minutes of gameplay, the others weren't as bad in terms of lost time, but still annoying. One was just as the boss fight was starting, the other in a random hallway in the Citadel near the end of the game. This is on Win 10, Intel + Nvidia, didn't fiddle with any compatibility settings.

I think Nvidia turbulence is the main problem for the crashing.