I have found that when I get a mission to "find the so and so item and describe it to me and kill everyone inside" that the mission doesn't complete after looking at or picking up the mission objective. Yes, I did kill all mobs in the mission area.
I tried this on a few missions and I wasn't able to complete any of them. I discussed this with another player and he said he was having the same problem.
Has anyone else noticed this? or have you been able to complete a mission of this type sucessfully since the 13.0 patch?