Hi Fake Pilot, see the FAQ answer here:
http://moi3d.com/faq#Q:_Why_does_show_points_work_for_some_objects_but_not_others.3F

You're probably currently trying to turn on control points for a solid that is made up of surfaces that join at trimmed edges. If you use Edit > Separate to break that object into individual separate surfaces, then you can select any of those surfaces and turn on their control points with Edit > Show pts.

Usually you can only edit single surfaces this way, not solids, with some exceptions for cases of a solid where all surfaces have their underlying surfaces naturally touching each other like with a box.

- Michael