P: Denoise fails in 15.0 (and all versions since 14.1.1)

[Ballonseide]

I updated Lightroom from 14.1.1 to 15.0 and AI Denoise has completely stopped working.

I have previously had Denoise failures with all other Lightroom versions higher than 14.1.1 that I have tried, which is why I've been using that version. Reverting to 14.1.1 always restores normal AI Denoise operation. I suspect there was a change to the Denoise implementation in 14.2 that causes it to consistently fail on my machine.

The exact problem as I'm experiencing it with 15.0 is as follows:

• Clicking on "Denoise" for the first time for a raw file causes the "Applying Denoise" progress popup to appear, but it disappears when progress is only about half-way through, and afterwards Denoise remains disabled (as does Raw Details).
• This repeats if I then click on "Denoise" again, but with the popup being visible for just a fraction of a second, if at all, and Denoise continues to be disabled afterwards.
• If I then click on "Raw Details", Raw Details are immediately applied without any issues.

(It seems to me the only thing actually being computed in these steps is Raw Details, not Denoise.)

• With Raw Details enabled, if I click on "Denoise" again, the Denoise progress popup will again very briefly appear and Denoise will then be enabled... but the image is not denoised, rather it shows as completely un-denoised, with massive chroma noise in high-ISO images that even classic noise reduction deals with easily. (It's exactly what I see in the 14.1.1 Denoise implementation, in the little preview window, as the "Without Enhance" comparison.)
• In this state, the Denoise slider starts out at its default 50 and is responsive, but doesn't cause any change in the image.

I've already tried creating a new catalog (same behavior, so not likely to be catalog corruption) and deleting Lightroom's "Camera Raw GPU Config.txt" file (no change). My GPU is properly recognized and utilized in all other GPU-related operations.

This issue occurs with all my raw files, e.g. with 14-bit losslessly compressed NEF files from a Nikon Z6. It's 100 % reproducible. I can provide a screen recording if it helps.

System Info

[alee88]

Experiencing the same behavior, very frustrating!!

[Sameer K]

Hey, @alee88. Thanks for the comment. If Denoise does not work, at all - Check the pinned comment from @Simon S Chen. 

If it is slow, or does not produce expected results, please feel free to start a new conversation with pertinent information such as the System info from Lightroom Classic and details about what you see. 

Thanks!
Sameer K
(Type '@' and type my name to mention me when you reply)