So, I'm having the issue of KAC is causing the game to freeze up when starting a flight. I've seen that this has been an issue in older versions, but nobody is apparently having this problem at the moment except me. I've removed all of my mods so I'm left with just the basic KSP 20.2 (which I fresh downloaded and installed to make sure) and KAC. I've tried every version of KAC from 1.4.1.0 to 2.1.2.0 with identical results. I start up the game, create a ship that is just the command pod in the VAB and try to start the flight. I let the game sit for ~10 minutes using 2.1.2.0 and still got no results. I do get the following in the output_log file regarding the incident: 6/13/2013 10:09:37 AM,KerbalAlarmClock,Active Vessel unreadable - resetting inqueue flag (Filename: C:/BuildAgent/work/7535de4ca26c26ac/Runtime/ExportGenerated/StandalonePlayer/UnityEngineDebug.cpp Line: 54) 6/13/2013 10:09:37 AM,KerbalAlarmClock,Adding DrawGUI to PostRender Queue (Filename: C:/BuildAgent/work/7535de4ca26c26ac/Runtime/ExportGenerated/StandalonePlayer/UnityEngineDebug.cpp Line: 54) 6/13/2013 10:09:37 AM,KerbalAlarmClock,Starting Version Check-No current web version stored (Filename: C:/BuildAgent/work/7535de4ca26c26ac/Runtime/ExportGenerated/StandalonePlayer/UnityEngineDebug.cpp Line: 54) 6/13/2013 10:09:37 AM,KerbalAlarmClock,Reading version from Web (Filename: C:/BuildAgent/work/7535de4ca26c26ac/Runtime/ExportGenerated/StandalonePlayer/UnityEngineDebug.cpp Line: 54) I'm pretty much out of ideas when it comes to what is setting me apart from others, so any ideas would be appreciated. I have no problems running any other mods from a pretty long list of ones I use on a regular basis. But as some people have already commented: This mod is really invaluable when it comes to running several concurrent flights. If you need more info, just let me know and I'll do what I can. Thanks in advance.