ok... i'll answer every possibility to make sure i answer ya
if you mean how to make the player see the waypoints in the missions, well just place them where u want, and once it is exported into single mission, all those who play it in cadet mode, will see the waypoints.
if you mean see the actual waypoints on the map, then set the waypoint to visible always or visible to cadet.
if you mean why you can't see the waypoints in the mission editor, this is because it just doesnt let u see them (weird hey?) - don't worry, they will appear once the mission is exported to SP - a trick is to load up a single mission, play like 2 secs of it, and then enter the mission editor - apparently this makes the waypoints appear...
hope that helps :thumbsup: