I am having the same problem too post patch trials

I had the same problem after creating a ship in multiplayer which then in turn caused all games on creation to crash.  I ended up deleting the new ship I created in the folder Derek Paxton mentioned above here in ..\Documents\My Games\GalCiv3\Designs  If you noticed it crashing after something like that you could try deleting your most recent ships created.  Once I deleted that "bad ship" it fixed my game and I could create a new game.  

Interesting thing is I could still load previous saves but I think that is because it was not loading the corrupt ship design since my load was from before the ship was created.

Thank you and I can also correlate with you on the fact that an earlier game could be loaded and not crash

So I tried re-naming as well as deleting the my documents directory data. Didn't work, every time I do that, after starting a game, it reloads everything. I feel like it has something to do with factions, I have two that I have used with the beta that keep reappearing no matter what I delete or reinstall. I will follow that link and see what we can do. Thanks for the responses

GUys,

I think after renaming to the .old file after following these steps some of which may or may not be applicable to you

https://esupport.stardock.com/index.php?/default_import/Knowledgebase/Article/View/496/161/general-galactic-civilizations-iii-troubleshooting

So far my game has not crashed.  Emphasis on steam settings

-Refreshing your Steam Files

Turning off Steam Overlay

Not sure exaclty what fixed my issue but, by creating a new directory after following the link above top to bottom, I have not had an issue yet.  

I do want to emphasize that when the game does seem like it will crash, the mouse cursor will momentarily go in to timer mode and slightly go to windows but resume game as if there was no issue.

not sure if this is how it should be but so far I am able to play offline mode with no issue.