Unable to get all side missions trophy Bl2

Don’t even know the mission. The description is mayhem awaits. Bring friends. It’s in arid -badlands. This happened to me on 360 a long time ago, and it’s not even patched. Lame.

After a quick Google search, I came across this:

http://oldforums.gearboxsoftware.com/showthread.php?t=300872

I’ve already tried this. Nothing works. This mission appears under badlands, yet there’s nothing here.

Forgot to mentionn since I’ve done that dlc mission, it doesn’t even appear on side quest mission…