by jwc » Thu Dec 10, 2020 6:17 am
The error message says you are trying to use a mesh that has a face with more than 4 vertices.
Makeclothes cannot handle this.
In Blender, edit mode, select a single face on your clothing item and look at the information about what you have selected.
It should say: 1 face, 4 edges, and 4 verts.
To find the offending faces:
Select Similar, Polygon Sides
This will select all the good faces with 4 edges.
Then
Hide Selected
and what is left are faces with other than 4 verts.
These faces must be modified, how to do that depends on your topology.
Adding more faces and working toward edges or merging adjoining faces usually helps.