Hello. This looks like the problem that occurs on M1 (or M2) Macs that can be resolved by setting the applications to “Open using Rosetta” – see Define not showing photos correctly where I explain how to change it.
I installed Nik 6 a couple of weeks ago, and the two Sharpener apps still need to be set to “Open using Rosetta” on my Mac mini M1. However, DxO says these apps are being rewritten (see https://support.dxo.com/hc/en-us/articles/4850799977501-What-are-the-new-features-) for release later this summer. So after that, Rosetta emulation will likely no longer be required.
Yes, mine shows as a universal application also (on my Mac mini M1). And it does run, either by opening from Lightroom or standalone. However, if I don’t set it to “Open using Rosetta”:
I can open a JPG and it works okay.
If I open a TIF image, the screen is pixelated as HerveB shows above, or like this:
If set it back to “Open using Rosetta” – then TIF files process correctly.
I suppose it might behave differently on different M1 or M2 Macs, but I was pointing out that I can reproduce the problem with TIF files (with version 6 Nik) and there was a circumvention that works fine.