Please explain me why i get double vertex on Extrude, it is an error on the program, or a Wrong setting?
I have a model that works on the conversions, but When i Extrude faces and edges, i get double vertexes on the same edge. EX: what appears to be a single edge, in fact are 2, with 4 vertexes.
I reffer to the Dog free tutorial part 4, mouth interior, in the tutorial the things work different.
Can anyone illuminate me?

Whe i convert the poligon to subD i get the next error:

// Error: polyToSubdiv1 (Poly To Subdiv Node): Cannot create subdivision surface as the resulting surface would have more base mesh faces (1041) than the maximum allowed (1000).
// To increase maximum allowed, change Maximum Base Mesh Faces in Convert to Subdiv Options. //

Thanks very much.