Stardock will be closed for the week starting on Monday, June 29th and we will be returning on Monday, July 6th. We will be monitoring support tickets and forums during this time but expect delays in responses during this time.
GalCiv3 Forums
Has been reported before on older versions, still happening randomly if you were not aware. 
It seems to be much rarer than it was before, but I got my first instance of it under .97 earlier today. It seem to me that it only appears when I've been running the game a long time, which suggests some sort of corruption error. I wonder if there is anything interesting in the debug.err file when this occurs. I think I'll take a peek at it the next time it happens to me (if it does).
I find it also happens more frequently when you save and load a lot in a short period of time. Maybe when your loading its not cleaning some data, or sometimes I save then load an old save right away while the game is still saving it the background. U know its still saving when it had "~savename".
Thanks for posting your issue, please make sure that your graphics drivers are up to date. If that doesn't help please submit a ticket to support and be sure to attach your support tool files.
Link to forums for explanation:
https://forums.galciv3.com/452855/page/1/
Link to support tool:
http://sd.stardock.com/Support/supportToolTest/SDSupportTool.exe
Thanks for posting your issue, please make sure that your graphics drivers are up to date. If that doesn't help please submit a ticket to support and be sure to attach your support tool files.
Link to forums for explanation:
https://forums.galciv3.com/452855/page/1/
Link to support tool:
http://sd.stardock.com/Support/supportToolTest/SDSupportTool.exe
Welcome Guest! Please take the time to register with us.