Under the Humanoid.RootPart documentation section it makes reference to the Model.PrimaryPart for R6 and R15 models, but says nothing of why you are telling us this? Is Model.PrimaryPart related to Humanoid.RootPart in some way other than possible convenience?
Also would be helpful to explain why this property is ReadOnly. How do we go about setting it?
Affected URL: https://create.roblox.com/docs/reference/engine/classes/Humanoid#RootPart