P: Colored "pixel" artifacts/subdued blacks in shadow areas (older Macs) (also visible on CR)

Also exporting with same issue as a .jpg desite not seeing it inside LR on the image.

@nealedel, please do the LR menu command Help > System Info and copy/paste the entire contents here so we can see exactly which versions of hardware and software LR thinks you're running and important LR options that are set.

If you're on Mac, click the Apple icon in the upper-left corner and do About This Mac. Post a full-resolution screenshot (not a phone pic) of the About window.

I want this banding off, what is it? Please help!! 

Quel système vous avez et quel mac?

j'avais aussi des probleme d'affichage avec le 12quand j'ai oncter adobe il m'ont dit que mon mac etait trop vieux.

alors que c'etait clairment un bug car le probleme n'etait pas constant.

Hallo!

Ich hatt vor ein paar Tagen das neue LR Update gemacht und seither habe ich ziemliche Probleme. Und zwar sind auf allen Bildern farbige Markierungen sichtbar (siehe Youtube Video). Habe das Update wieder deinstalliert, doch das Problem tritt weiterhin auf. Erst wenn ich das Programm schliesse und wieder öffne, verschwinder der Fehler für kurze Zeit, erscheint aber nach ein paar Minuten erneut. 

Kann mir jemand helfen? Vielen Dank!

https://youtu.be/Ff1jkcWMjMo

I have a macbook pro 15 inches in 2015, Monterey
, when switching to lightroom 13, a truncation of shadows and bugs appeared in the shadows, I reinstalled the system on the macbook, reinstalled the lightrum did not help, my GPU was disabled earlier because of similar errors. now it is disabled and the error does not seem to be disabled. I have a photo catalog that I've been processing for a week and now I can't display on my computer, my friends' computer displays photos of norms.
I rolled back the version to 12 and the error disappeared. what is that?

Hello everyone, even though this place is intended, I hope, for Adobe technicians. I have a major and urgent issue with Lightroom that I've been carrying since version 12 - currently, I have version 13 installed on my late 2013 Mac Pro.
In the Develop module, the images appear degraded, and the blacks show up as pastel black spots. These images are not deliverable to clients!! Instead of the spots, sometimes there are cutouts similar to highlights and shadows but in various colors: red, yellow, blue, and white.
I urgently need to resolve this issue because I am a professional photographer and I'm having difficulty delivering my work. I noticed that the problem doesn't occur if I change the SETTINGS-PROCESS VERSION and select version 4.
I've tried disabling the GPU, but the issue still persists. Thinking it might be a computer problem, I restored my Mac Pro to its original settings, but the problem immediately resurfaced. Can anyone help me? Sorry for the errors... I'm Italian and don't speak English well, and I'm getting assistance from ChatGPT.