I have already solved this problem on my end but just want to throw this out there...
I recently had to re-install windows on my laptop. Afterwhich I had to re-install galciv2 and StardockCentral. After installing the latest beta with SDC however, a scary popup prevented my from actually playing the game. "Your game has apparently been activated but either the serial number or SID is incorrect". This popup appeared everytime i click on the EXE. I then tried to get my serial number again from SDC.. A totally new number was sent to my email. After using the "Update Serial" in the launcher, i still got the popup. Then again after re-installing the beta i still got the popup. Then after uninstalling the GAME ITSELF and reinstalling I STILL GOT THE POPUP even though i used the new serial each time. Finally I got it to work:
1. Uninstall BOTH SDC and Galciv 2
2. Reinstall and Login to SDC.
3. Get latest Serial from SDC
4. Use latest serial during installation of Galciv 2.
5. Install Beta via SDC.
I then invaded Korx. yum.
I might have missed something and that's why i went to all that grief but i heres hoping that this helps some other clueless bastard out there.