XnView Software

yes, that's what I tried. Same error message if I try to open from the XnView Browser

No, it does not work. "File can't be loaded!" is the error message. Same as before.

Now I think I understand what you mean...guess browsing with XnView

Yes, it works fine.

I am not 100% sure what you mean.

In one of my screenshots I did browse it, right?

additional Info:
"open with..." and choosing different apps works fine (tested with chrome.app, safari.app, preview.app)

Same here on Sequoia (15.5) and XnViewMP 1.9.2

Files stored in pCloud.

If the directory name is "König (T17)" I cannot open any file inside. Is it spelled "Koenig (T17)" it works fine.

regards