When using CreateHumanoidModelFromDescription to load R6 characters via the second parameter, the name of the model is always “erik.cassel” (regardless of the description provided)
If I recall correctly, this is because those are the names of the models located in the game’s files in the \Roblox\Versions\version-x\content\avatar directory. Try loading the character.rbxm and the characterR15.rbxm models and the names should match up.
Thanks for your patience, As of now, this issue should now be resolved! If this issue is still occurring, please create a new topic for us to look into.