Let it work, all the time, never let it stop loading the video.
Next, open a quick match on free for all. Just wait! Your internet connection will be fucked up, and you will be playing with bots.
Sometimes u need to play several maps before get into Boneyard, but you can do it, it's just time consuming.
saw your comment for the Bromageddon Halo 4 achievement. If you were serious and you need/want someone to do co-op with when it comes out, just msg/add me on LIVE: TenDahlaG4mrTag. I'll be running through this game multiple times anyway.