What causes CTDs most often?

[louisjk1990]

Not specifically related to SS2 (maybe) but all of a sudden im getting a lot of CTDs. Cant say its any particular action/location/event/fast travel thats causing it, just seems to be every hour to a couple of hours ill get one. My question is, is there a way of determining what caused it? ive had the saves open on Resaver and doesnt look to be a lot of active scripts on the saves so not sure if its script log, but ofc it could be because unless its a fast travel CTD, you dont often have a save just before it happens.

 

[Cessori]

I can recommend using Buffout 4 to discover the reasons for CTDs.
It has installation instructions that need to be followed for it to work properly.

 

[Blitzcraig]

For reasons I gave up trying to diagnose, my game crashes like hell when in fullscreen mode but when in windowed mode it runs smooth as a kitten.

 

[msalaba]

For nVidia users:
I have found certain nVidia driver versions can cause CTDs. (IIRC, 495 series) I haven't had issues with the last few versions.
Having flex enabled can also cause random CTDs. Add this to Fallout4Custom.ini to disable:

[NVFlex] 
bNVFlexEnable=0 
iQuality=0 
bNVFlexInstanceDebris=0 
bNVFlexDrawDebris=0