I'd like to give this thread a bump since I have the same issue and could not find any solutions. System: Win 7 64b, 16 GB RAM KSP: 0.90.0 32bit Problem: Exactly as in initial post. I'd also add that GUI elements can be clicked but don't seem to do anything (except the menu button). Time is frozen, time warp does nothing. Mods installed: MechJeb Kerbal Attachment System Firespitter Various parts All mods are up to date. More background: KSP behaves exactly as described in the initial post, the only difference being that I'm playing in sandbox mode. I updated KSP earlier today from .24.2 since I hadn't played in a while and have had this issue since then. I played my old version yesterday without issues. The backup copy of that version runs fine. Starting a new game also works fine. I started a career game to see what would happen it seems to load normally every time. After starting the new game I was also able to go back to the menu and repeatedly load the old game successfully. However, after a restart of KSP this no longer works either. I have also tried creating another new game (my third) but it had no effect. My sandbox game has been running since I started some years ago. Needless to say, there are a few missions running I'd like to see completed some day. Any help fixing this would be appreciated.