seems logical... anyone has an idea how to change it?

Found the ansear on Arelith forum, thought I could share it:
"Go to my computer and find the folder that says NWN, then find the tab called nwnplayer.ini Open it and find DisablePartyInvitePopup=1 it should be at the bottom of the first segment, replace the 1 with a 0 so it looks like this DisablePartyInvitePopup=0 save and exit. The party invite pop ups should now come up."
Thanks slkNihilus for the tip!
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edit: guess I'm not refreshing this page too often;)
thanks everyone for help, it works now!