Long time no see, I’ve finally finished the retopo in Topogun, looks great then I imported the model into maya as an obj like so:

All the normals are facing the right direction, when I subdivide it looks perfect and smooth but I try to delete half of the model to work on the symmetry I select the vertices and hit Delete and I get this message:
// Warning: Some selected vertices have complex edge attachment; Delete Edge/Vertex removes selected vertices and related edges
So I went in Edit Mesh > Delete Vertice/Edge and this is what happens:

Not everything gets deleted and I can’t make those parts go away, they break the other half of the model when I try to delete, I need help please, is it something wrong with the obj?
Thanks!