There is currently a bug that some players experience that involves not getting the quest "Meeting of the Silver Hand". This is part of the Paladin Order Hall Questline, and it will probably be fixed in the future, but currently there is a good workaround if you have the problem.
So, this is for players that cannot get the quest, even though they are supposed to. You solve it by going to Dalaran and find Archmage Khadgar in The Violet Citadel. He will offer the quest "A Falling Star", which you need to accept and do. Once you have placed the Light's Heart in your Class Hall you get a new quest by Lord Grayson Shadowbreaker near the mission map, which can be accepted if you are not in a party or raid. This will allow you to start the quest "Meeting of the Silver Hand"!
If you are also having problems finding Justicar Julia Celeste, make sure to go outside into Eastern Plaguelands. A lot of players are having trouble finding her. Also be sure that Lady Liadrin is not on a mission, or is assigned as your combat ally, because this will prevent you from finding her for the quest.