Hi,

For some time every opening of the File Dialog is preceded by the subject message. It's just an annoyance, yet I'd like to get rid of it. I was not able to discover exactly this case. I can't even guess what the tags folder is

File Dialog in what application?

In any (KDE, Qt-based) application.

Well, I have never seen such a message, could you please give a concret example how to reproduce this, and maybe your exact Plasma version and distribution?

Apparently, it has nothing to do with the Plasma version and things like that. There are several boxes with the same Manjaro KDE installation; there is but one with the problem in question. No, I don't know how to reproduce it; it just happened some day and refused to go.

Something like this is here, but tags folder is something cryptic.

The forum post you linked to is about snap packages of Kdenlive that can't access the /media folder, maybe check if you have Snap sources? This is a specific problem with Snap packages, if you don't really have to use Snap I strongly suggest avoiding that kind of sources.