Adult quest MC item Bug:
If you're having the same problem i had (Clicking the MC item and getting this error)
Then its most likely because you clicked the item after accepting the quest
so you have to forfeit you're quest from the Quest Log(click J) if you see it just do it, if not then you have to forfeit all your quests and delete you're quest items your quest log should look like this
now just re-login and you should see the mission forfeit it and click the item again.
this should work it worked for me
after you click your item you'll see this on your map
go to that NPC finish all his mission
hope this helps all of you with this problem
and have a good day.. 
