The DeNoise feature on Lightroom Classic is not working

Hi - 

The DeNoise feature on Lightroom Classic is not working.  The last update I did was 15.3.1.  No current updates are available that I can see.  I’ve tried it on a few different photos in a couple of different folders.  It’s not working on anything I tried.

Google AE is saying “users on versions 15.3 and earlier may experience "Denoise model version mismatch" errors, requiring an update to version 15.4 or later.”  

If this is true, I don’t see how to update to 5.4 or higher.

Can someone help?  Thanks.  

Jan Noto