I didn't make it!
First off, I have been modding FOC for some time now and this problem occurred recently when tampering with the XML files. When I load the game and try to play galactic conquest as the Consortium, an exception occurs and the game crashes. If I try to play galactic conquest as the Rebellion, the same thing happens. But here is where things get interesting. When I select the Empire, it works perfectly. No problems. No exceptions. It just works as if the other two factions were working as well. Also, I'm able to play as the Consortium and the Rebellion in skirmish. So I'm assuming it has to do something with the Galactic Conquest files, but I'm just not sure what. Any help or ideas would be greatly appreciated.
Maybe you messed with the stories? Could be or something with the heroes in GC. Actually it could be a lot of things but you can try and replace some files and seek out the problem that way.