I suddenly ran into a bug where I couldn't upload my avatar.
I've uploaded several avatars, but this is the first time I can't cope.
Detaching the Blueprint ID of the Pipeline Manager does not solve the problem.
The error message is:
the signed in account does not have acces to the blueprint associated with your VRC_Avatar(or Scene) Descriptor.
Please sign in with the correct account or detach the Blueprint ID (accessible on the VRC_PipelineManager) associated with the descriptor.