maya8+ ?

try one of the following workarounds. since autodesk bought the pack the UV editor is pretty buggy programmed in my opinion (besides some other issues).


1) extract an element or face from your object and combine geometries again. delete history - eventually blind nodes in hypergraph also. this works well before using boolean operations or closing holes too - I get the same fatal errors there quite some times.

2) convert the poly to subdivision and back to poly (with control points checked in the options box) be aware that all the uvs get split with this procedure. uvs still look the same tho and go well with applied textures, in case it doesn´t really matter for you.

3) in any case - delete all blind nodes in the hypergraph.