Nvwgf2um.dll exception DX11

Has anyone else seen this error with dx11
Seems its gfx driver issue, I’ve been soak testing a pc, after 16hours, I get an excpetion and v4 crashes, I’ve done some searching but to no avial, anyone seen it, any suggestions of a fix? The only suggestion I’ve found is to roll back to 306.97, but that wont install and says it cant find compatible hardware, the gfx card is a 660ti…

Any specific node creates the issue?

Or just a plain renderer?

So I think I’ve worked out what was causing this, I was setting some subpatches to evaluate =0 they contian various fx unused at the time, the error occurs when switching between these fx, I was also switching the output textures of these fx via a switch node, I’ve replaced this with a texturefx and using cases.
I’ll report back if its the texturefx that fixed it or just using enables instead of evaluate.
I managed to get the crash time down to 1.5hrs by switching fx every .2 seconds!

Ok so its the switch node that was doing it, I was setting all the subpatches to not evaluate, but the switch node was not liking it somehow…
Attached is a switch fx using case, which I’ve seen in a shaders here, so thought I’d show its use…

Switch Inputs as texture FX (1.6 kB)