Compatibility packs have been released alongside each Borderlands 2 add-on in order to allow gamers to continue playing online with other party members regardless of whether they've bought specific DLC or not.
According to Examiner, affected Xbox 360 users are finding that the most recent compatibility pack is stalling at 99 per cent during downloading and never completing.
In its latest update on the issue, which was posted on Twitter about seven hours ago, Gearbox said: "We're working with Microsoft to get the Compatibility Pack download error on Xbox 360 addressed ASAP -- will share updates here as we can."
Sir Hammerlock's Big Game Hunt will launch today on PC, Xbox 360 and PS3 (tomorrow on PS3 in Europe and Oceania). Check out the launch trailer here.