Quote - Not sure if its been mentioned already, but in case you are running Windows 7 it might be some UAC (User Access Control)  awkwardness at play.

Try starting Poser with 'Run As Administrator' and then proceed as you were to see if that makes any difference at all.

 If it does, then consider disabling UAC or, installing Poser to some place other than the default location of Program files etc...

If you're not on Win 7 or Vista ignore the above - the problem lies somewhere else.

Finally had a few minutes to actually try this. So, first I commented out the localhosts ::1 thingie in hosts. And put FFRender (as well as Poser Pro 2010) in the firewall as allowed programmes, for local network and internet. And ran PP2010 as administrator.

In the message section of Queue Manager (at the bottom) it says:

Cmd port 4418, discovery port 11523

...with periods that sort-of scroll out and go back to 1

And there's this endless list of:

Launching FFRender for parsing...

..FFRender failed to launch.

So, no joy, here.

ETA: I have submitted a problem report to SM.

Monterey/Mint21.x/Win10 - Blender3.x - PP11.3(cm) - Musescore3.6.2

Wir sind gewohnt, daß die Menschen verhöhnen was sie nicht verstehen
[it is clear that humans have contempt for that which they do not understand] 

Metaphor of Chooks