SolarField: Been having the same issue. Game crashes quite often in Velen (Was fine before that). Could be while playing, or in the menu (sometimes equipping a sword can crash the game). It's my first playthrough, I was waiting for the game to be more stable, guess I could have waited a bit more...
Edit: After some test, I think Frame Generation is the problem for me. The game crashes very often (especially in the menu) with DLSS 3 on, but it's more stable without it (not perfect, but better). I do hope they will fix this as the framerate is quite low without Frame generation (at least on my 4080).
I think 4.02 or 4.03 was more stable than 4.04.
I wish I could downgrade to 3.x something and play that, sure it might look a bit uglier but at least it didn't crash all the time.