Hello ! A strange problem appeared two weeks ago, no significant change to the game were made and reinstalling it didn't fix the issue !
I play KSP in full screen mode, and when I unfocus KSP (opening my browser, alt-tabbing etc..) the game starts to lag tremendously, I get like 3 FPS... Which is really inconvenient as you may imagine !
I have Kerbal Engineer, SSTU, persistent rotation, probes plus, decals, Direct launch vehicles and Space shuttle payloads.. Running ksp in vanilla doesn't fix the problem, I've checked the logs, no errors when the lag occurs...
Good day,
-Luca