(On one ol’ 'puter) This quarterly pkg-upgrade moved python from 3.9 to 3.11 - but (as usual) not every py-package got upgraded: py3xx-xdg didn’t - and NomadBSD needs it to be in sync w/ python.
This command should optimally return empty-handed:
> pkg prime-list | grep py39
If you (like me) got the result:
py39-xdg
You should do the following:
> sudo pkg remove py39-xdg
> sudo pkg install py311-xdg
If the first command returned other packages than xdg, you should look into updating them too 
BSD-regards
Ludensen
PS.
And with such an old NomadBSD (w Openbox) you could consider researching if the lock on certain packages is still necessary…