Kerbal Space Program

A consistent repeatable error occurs in vanilla KSP v1.2.2.1622 (OSXPlayer) installed via Steam on OSX whereby the in-game menu options (deploy drill, shutdown engine, aim camera etc.) fail unexpectedly. This issue persists until the in-game instance is changed (e.g. user returns to space centre, tracking station etc.) whereupon it reverts to normal upon flying the craft once again.

To repeatably generate this error:
1
From any new or existing game, launch in-game state (e.g. "launch" a manned command pod on launchpad)
Right mouse click on any relevant part
Buttons will register click and function normally
2
Menu -> save... -> [any filename] -> Press "enter" (do not click "ok" button)
(If save file already exists then additional step generated, but this makes no difference to error)
Game state returns
Right mouse click on relevant part
Buttons will not register click (including "aim camera" or "rename vessel" - i.e. this is not a remote control issue)
3
Return to Tracking Station
Immediately fly previous craft
Right mouse click on relevant part
Buttons will now register click and function normally again

The issue appears to be around the use of "enter" for save game filename confirmation, as clicking "ok" instead will not generate this error.