Why can't I build this avatar?


I’m working on a VRChat avatar, but I’m unable to build it for testing. In the Builder menu, I see the following message:

Spine hierarchy missing elements, please map: Shoulders.


I didn’t include shoulder bones in this avatar because they’re listed as optional in the Avatar Definition configuration menu:


Why is this preventing me from building the avatar?

This resource might be helpful: https://creators.vrchat.com/avatars/rig-requirements/#spine-hierarchy

Note that:

Spine hierarchy missing elements, make sure that Pelvis, Spine, Chest, Neck and Shoulders are mapped.

These bones must all be mapped. If you get this message make sure none of these slots are empty. Note that the Neck and Chest slots are optional for Mecanim, but required for VRChat.

They are optional for the rig creator, but required for vrchat, itself for a humanoid rig.