Zero UV area or surface area on mesh

What causes the following error,

Zero UV area or surface area on mesh.

And how can this be corrected?

Hi there,

I know it’s very old, but since I’ve been having the same issue, figured it would be useful for somebody else if I posted it here. I replied (Username Aze_) to a different thread here: https://forum.unity.com/threads/zero-uv-area-or-surface-area-on-mesh.343508/

I hope this helps people with the problem today,

Cheers,
Charles