A work mate is having issues with leaders in Rhino 6. Some do not show control points when selected nor when _PointsOn is run. Other leaders do work as expected. The only difference we can see is that the bogus leader does not have text assigned to it, but that does not consistently cause the problem.
Note I will upload the dodgy leader when my work mate and I work through why the original export is crashing my rhino, or maybe that is part of the problem.