Microsoft and Call of Duty publisher Activision are aware that players are running into some issues with the first big pack of downloadable content for Advance Warfare.

The futuristic military shooter’s Havoc expansion, which includes a new mode and maps, went live late last night on Xbox One and Xbox 360. While many people are happily enjoying the new content, some are having issues, such as a problem when they attempt to play the new Exo Zombies mode that pits players against hordes of the undead wearing jet packs. Others who previously had a season pass on Xbox 360 and tried to move it to Xbox One cannot install the Havoc DLC.

Microsoft updated its Xbox status page to acknowledge the problems, and it says that it is repairing what’s not working.

“Are you receiving an error message when attempting to play Exo Zombies in Call of Duty: Advanced Warfare on Xbox 360,” the Xbox Live status page reads. “Are you having difficulty installing the Havoc DLC after transferring a Season Pass from Xbox 360 to Xbox One? Hang in there, Xbox members. We’re moving toward a fix, and we’re grateful for your patience during this process.”

This is not the first time Call of Duty: Advance Warfare has had download issues on the Xbox One. In December, Activision unleashed a new weapon called the AE4 Widowmaker for the game to anyone who owns the season pass for Advance Warfare DLC. But many people struggled to download the item for more than a week. Today’s problems seem like a continuation of that.