Can't click on orbit lines to create nodes

[Crixomix]

So I've got this super weird bug. When I'm in the map view flying a ship, I can't click on the orbit lines to create a node, nor can I double click on things to get the "focus view" or "set as target" menu. When I first load up KSP, it all works fine. After a few minutes of messing around with nodes in the map view, all of a sudden I can't make nodes anymore. Saving & Loading does not fix it, neither does returning to main menu and coming back. I literally have to restart the game, which, essentially makes it unplayable as we all know how long it takes to restart KSP, and you just can't do that every 10 mins.

I've got half a million mods. Precise Manuever being the only one that messes with nodes, and then Kerbal Alarm Clock. 

Has anyone else had this issue or know how to fix it?

 

Edited March 30, 2018 by Crixomix