Unable to delete appearance

[FrodoLoggins]

Only 1 material in this assembly. Only 1 appearance applied to the assembly. Yet I am unable to delete Plastic-Glossy (Black) as Fusion thinks it's assigned to something. It is not assigned to anything. Highlighting the material and selecting Unassign and Delete does not remove the appearance from the Appearances dialogue:

.f3d file attached.

[ryan.bales]

It is applied to something - but not as an appearance. Their physical material is plastic glossy black. You'll need to modify the physical material in order to be able to remove it.

[russellcrockett]

Also unable to unassign and delete the physical material.