Are you trying to load games saved before Beta 4? The chances of saves made prior to Beta 4 have a high likelihood of being incompatible with Beta 4. It is not unusual for this to happen in any Beta cycle.

Hey Trescu,

Does this happen consistently with all of your saves? Additionally, you mention creating new saves, do the crashes occur after a new game has been created and you try to jump back into your game?

In the event this is something that occurs with all of your game saves, I'd like to grab a copy of your latest problematic save to see if I can duplicate the issue. There is some additional information that would be helpful to the troubleshooting/bug-hunting process, if you wouldn't mind, I would appreciate if you could place a ticket through our support system so I can forward the appropriate information to the development team.

Please see the last section at link below for help with placing a ticket:

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