It is crashing because it is looking for a tech specialization in the Terran Engineering tree that doesn't exist.
No idea why a tech would be missing in your version, it works fine here. And its the type of issue that should blow up immediately for anyone playing as Terran (which is most people).
The only thing we can think of that can cause this is if you have some local mod or custom faciton info that is pointing to a tech def that doesn't exist anymore. To test for that please try these 2 things:
1. Disable mods in your game options, restart gc3 and then see if you still get the crash.
if that doesn't work:
2. Renaming your ..\Documents\My Games\GalCiv3 directory to GalCiv.old and then restart GalCiv. The game will recreate the directories, all of your prefs will be reset and it will clear out any local content you have.
Please let us know if either of these things fixes the issue for you.