Technical Can't open Dire maul north's courtyard door.

[JohnnyRF]

I know that I have to take the key from a box that an ogre called Fengus guards to open the door.
But I've also read that you can open the door by lockpicking or a Truesilver skeleton key (which I have 20 of)
I've been trying to open the door several times with the Truesilver skeleton key but it just says "invalid target" or something.
Any help?

[Meddildor]

i tryed open this door my cobalt keys. its not works.
think comments from wowhead can help understanding
// If you are doing the Dire Maul Tribute run, Guard Fengus is easily avoided by taking the route to the right of the room where he patrols (you'll see a group of ogres, and then a couple of groups of bugs, then a couple of packs of ogres/dogs). Fengus does not patrol this way, so there's no risk of accidentally aggroing him. Just send up a stealthy type of character to the middle of the room to retrieve the Gordok Courtyard Key and once secured, keep taking the right path until you clear up to the door. Be careful after you finish clearing the bugs as Fengus does patrol up to that corner. Don't forget to visit Fengus again after you've been "crowned" king and receive the "King" buff -- Fengus gives a very nice attack power buff that lasts for two hours! //

[x1195]

I noticed the box doesnt spawn if your dungeon difficulty is set to heroic, reset and put it on normal. It worked for me