I need to calculate engagement length of a srew and a thread with the Tolerane of course.

When I use coincident between the cone of the head and the cone of the CSK, I do not see it in the mates of the Tol analyst mating conditions procedure.

I tried to split the screw cone and the CSK cone faces and then add coincident between the two spliting lines. this gives me the option to chose and have a green light in the TolAnalyst window. If I press the arrow  Solidworks crashes....