Hi,
I am using V-Ray 6 - Windows 11.
Nnivida denoiser works in the vray frame buffer, but when using the separated tool → denoiser tool (VDenoise)
Engine → Default V-Ray works
But when I try VDenoise the same exr image with all vray specific aovs requested
Nvidia does not denoise (image stay the same without denoise). Do I have to add any specific AOV in the passes for work or maybe a specific driver from Nvidia?
Thanks in advance
For starters, try the suggestions on this page.
Great! Thanks Hermit!, I will fully check that page 
Hi Hermit,
To point out, I spent my last weekend investigating why it was not working on my PC which is a new pc.
Windows 11 pro 64bit. Intel 13900k. 128Gb. RTX 4090. (with all latest Nvidia drivers)
Then after several attempts, I realise that I had different versions/builds for the VDenoise. I also tested on my old PC and I got the same error with the latest build for VDenoise using the NVIDIA engine.
Then when I tried to use an old VDenoise build from “Dec 02, 2021”. The version that I found in the Houdini VRay folders.
This version FINALLY DID work Nvidia in Both PCS.
That means the actual VDenoise may have a problem with the actual build using Nvidia as the engine.
Hope helps
Thanks