While in game, press Alt Tab to switch windows or setting Borderless Window and Windows Mode in game settings causes the game to crash.
I found a solution to the above problem. However, I should add that there were no problems until the end of last year.
I have two PCs with an RTX 4080 and an RTX 2070. I encountered the above issue with the same version of the last epoch and NVIDIA driver version 591.86 and discovered this.
On a PC with an RTX 2070, pressing Alt-Tab did not cause any crashes in either borderless windowed or windowed mode.
The cause of the crash was the Smooth Motion feature, which was supported on the RTX 40 series. Applying this feature from the NVIDIA application in the last epoch caused a crash.
You can avoid this crash by turning off the Smooth Motion feature.