This means you are out of memory... either on your computer or the game this happened to me what you do is look up "orbiter" in "my comuter" then delete all files then go to http://www.orbitsim.com/ and get orbit from one of the mirror sites (I prefer the Huntsville, Alabama one[i think that is http://www.m64.com/ but not sure. email me at [email protected] or IM me(I use yahoo messenger) [email protected] if this does or doesn't work.