On the Same server?;
#party/platoon invite unavailable?
woven plinth
weak fractal
the receiver may be in a party already or have invites off
obtuse kraken
Or ist talking to an NPC, the black spirit, is on the map,... It sometimes happens without any trigger. Go into if both go into character selection and login back it should be solved.
keen shadow
same server and invites ok, already went char selection and back stil nothing
like whatever
golden anvil
Go to your settings. Turn reject party invites on, apply, off again, apply.