Current build of the Lazor system is causing this bug with all saves, all crafts, as repeated above. I launch, and so long as the craft I'm flying is selected, I can use the EVALazor and the Lazor systems, however once I switch control to another craft or go to the Space Center and back, everything stops working. Not sure if it caused this to happen, but when trying to work on my Space Station in Lunar Orbit, once my Kerbal got close enough and switched on his lazor, the SS went crazy into a shake, breaking apart all my solar panelling, making my job much more difficult; now I have decided I might just have to start the save all over again (for the fifth time, sigh.)