Question Avatar Creation Failed due to 'Ambiguity'

Hi, I'm new to Unity (like, installed it to do this one thing and never plan on using it again, really) and I just want to make a VRM model.
I have everything done in Blender. I weight-painted the entire model. I exported to .fbx. I made the materials. I got everything set up. But for some reason, I can't create an avatar because

"[filename] avatar creation failed: Ambiguous Transform: 'Head' and 'Armature/Hips/Chest/Neck/Head' found in hierarchy for human bone 'Head'. Transform name mapped to a human bone must be unique."

I have no idea what it's saying and I can't find anything on this issue online. I only have one head bone and it certainly doesn't seem to contain a brain I can use to solve this issue.

 

Figured it out. Unity recognized part of the mesh as a bone. I have no idea why it did that. I just merged the "Head" mesh with the "Body" mesh in Blender and re-exported it. Works fine. Leaving this up if anybody else has this problem.

 

One can use Mixamo as a debugging tool also.
Thanks.

 

For me at least it seems naming the head mesh "head" confuses unity, changing it to anything else fixes it