Problem with Nightfall

okay, so for the protector title, it says i need 20/20 missions, atm im at 17/20 missions with all missions done.. i cant complete Poghan Passage, as i did the other one, and i cant complete Dasha Vestibule, and Nunudu Bay, as i selected the other ones. so im not sure on how to get these missions done

Help accepted, thanks

Once you're finished the game, you should be able to access the heroes you didn't choose during the storyline via quests (I believe I got the quests in the end-game area, I may be mistaken), and thus should be able to then complete the missions you missed, like the one that requires the Whispers necro guy if you took Margrid.

If you have trouble, check the wiki for those particular missions, there should be a note on how to start them if you took the alternate path. Or simply team up with someone that has the required heroes.

Ive tried all of that, and nothing worked.

I have Margrid, and ive completed her quests, and im partied with someone who needs the mission, and has the required hero.

still not understanding

With Margrid in your party, talk to Jack of Truths in Poghan Passage, see if that lets you do the mission. If that doesn't work, see if you have finished/can get the quest 'No Me, No Kormir'.

http://guildwars.wikia.com/wiki/No_Me,_No_Kormir

Edit: You know, it would be awesome, if GW had a 'Completed Quest' log.

Try walking to them, then once there talk to the mission starter, there will be a dialogue, look at it closely. I did Melonni and I'm in the process of doing the missions for koss.

Been a while but seems like after I finished Abaddons gate I was able to click on and add the missing heros while I in the Throne of Secrets?

When you complete the last mission, you can get quests to pick up the other heroes, in the end-game area.
Also, you can complete those missions if you have someone else in your party that has the required hero. You may need to do some other preliminary quests with that hero too.
http://guildwars.wikia.com/wiki/Miss...28Nightfall%29