Getallsolids method vba doesn't work

Hello. 

Why this method doesn't work?

By this way the similar method GetAllLinearMembers from the same library works perfect.

Sub stf()

Dim mylist2 As STFSolidList
Set mylist2 = New STFSolidList
Set mylist2 = STFApplication.GetAllSolids(ActiveModelReference)
Debug.Print mylist2.GetCount   'ERROR OBJECT doesn set

end sub