Yes, as a matter of fact I did that before starting the game that showed the problem.  It said that one file was "corrupted" and would be downloaded, which it did.  When I started the game I found that all of my saved options had been reset to the default, so I'm thinking that the prefs.ini file is the one that was "corrupted".  But that's a separate problem.

Anyway, corrupted files are not the cause of the tech tree problem.

This problem usually happens to me every playing session. I sometimes occurs on reloading the game. It always occurs when I play 2+hours at a time. The names disappearing on the tech window is always a precursor to the game becoming sluggish and the UI disappearing all together. I figured it's just a memory leak and kept on truckin'!

When this occurs, I just save the game, close the game, then launch the game again, load my game and the issue is gone for another 2+ hours. I don't think any save game files will show anything because relaunching the game with the save always get the issue to disappear for a while.

Reloads the game with the same settings but generates a new map. Especially useful for randomly generated maps.

Thanks, it seems you do.  I've tried multiple control-Ns, and loading a save from within a save, and can't get the problem to occur.

Tell her she can have the weekend off!