A few users are affected by this bug, most aren't. And we don't know what is causing it.
Here is what I suggested someone else try.
A few more ideas.
Go to Galactic Civilizations III\DLC\EXP3_Intrigue\English and delete the Text folder, then verify integrity of files.
If that doesn't work the last resort would be to delete all GC3 files as instructed here
and reinstall. Make sure to backup any civs and ship designs before doing this.
Please inform me if this solves your issue.
One more thing, do either of you use an anti-virus program? Sometimes they block files from installing.