Suggestions:
1st : is it an old game (from savegame) or new game? if it's old, you might want to try starting out a new game, unfortunately savegames are very often incompatible between different game versions.
2nd : if you got a Mod, uncheck the "Use Mods" checkbox in the game options https://www.galciv.wikia.com/wiki/Game_Options (might want to check that out even if you're not sure just in case)
3rd : try to move or rename the "\Galciv2" folder located somewhere in "My Documents\My Games" (this should reset all your settings BUT will allow you to keep your data untouched)
if any of the above does not work, you might want to do any of the below in no particular order depending on your current mood
4th : you might want to provide us with the content of the "debug.err" file which should be located in "My Documents\My Games\Galciv2" (just after launching the game and having the problem again), that may help us to help you...
5th : uninstall the game, delete the game folder and reinstall the game.
