
Roblox has updated some bundles like Robloxian 2.0, these new meshes will not load which is a bug. I think the superhero bundle was also changed?, Simple solution is returning the assetdelivery result of an older version. Example:
https://assetdelivery.roblox.com/v1/asset/?id=ASSETID&version=VERSION
https://assetdelivery.roblox.com/v1/asset/?id=ASSETID&version=VERSION