I have multipled mia_material assigned to a single mesh , and most of the time if i try to assign yet another material on selected faces i get this error . I have never encountered this problem with maya shaders ( applied dozens on a single mesh ) , but this problem has been coming again and again .
For a workaround , a re-applied all lambert shaders on the model and connect the mia_material and their respective SG but still it didnt help much .
anyone else faced this problem ??