Latest Reports this morning say users are experiencing a major issue when trying to play Halo: Reach co-op online. Those playing the game on one of the new Xbox 360 4GB slim units are apparently locked out of the mode due to a lack of hard drive space on the console.

Players were greeted with the message "One or more players do not have the hard drive required for this game type."

Microsoft told GamingLargest the company is aware of the issue and are looking into it. We'll keep you updated if a solution is found.

Microsoft has since updated Halo: Reach's FAQ on the official website saying a hard drive is required, however.

"One or more players do not have a certified Xbox 360 hard drive attached to their Xbox 360 console. Some multiplayer aspects of Halo: Reach require an Xbox 360 certified hard drive."