I had initals and respawns placed on the map, but I died and couldn't respawn at all. I had a friend join and he couldn't even spawn in.
Overdoziz and his palindromes! I just got into someone else's map when he couldn't spawn, so maybe getting someone else to open it might work.
Did you just load it up yourself, or did you join in progress? I have the same issue for a couple of my WIP's. Tried to have someone join after I had loaded the map, but it didn' work.
I loaded it myself. It let me in and spawned me at a red Respawn point. Right now I have to go to the Xbox home screen, highlight halo, hit the menu/start button and then chose quit to restart the game just to avoid the"retrieving" screen.