There is a problem when defining a surface sets using faces from wedge elements. After export to an abaqus input file, the input file specifies the elements needed to define the surface set, but it does not contain the information about which face number from each element lies on the surface. This results in Abaqus printing an error, and not creating the surface.
The problem also seems to exist for surfaces defined using the faces of tetrahedral elements. I don’t think that I had this problem in trelis 15, but now, using trelis 16, the problem occurs.