Kerbal Space Program

Something has happened that has broken my save. When I try to move lights from inventory to inventory in a craft, or try placing them with an engineer, the lights "stick" to my pointer and do not place or drop into the inventory. I am forced to load a savegame, but even when I do that the light icon or texture is left floating in my screen (see attached). I have lights stored on my Minimus Space Station, and lights I want to move on my Minmus Ore Extractor, and I cannot. Seems to affect all my craft. Started happening recently.

Example and version info in screen shot.

Save file exhibiting problem attached.

Zero mods, pure stock game.