I too have this error, but it is rather different from what most people are reporting and I am slowly becoming very angry with the game...
Some things to note:
1. The file in question that is refusing to load is a HOTSEAT game.
2. The game was started a few days ago on my computer. Since that time, I have re-installed CivIV.
3. Now after the re-install, the error pops up.
4. The save is on an NTFS partition but the game itself was originally FAT32. I have converted this volume also to NTFS now but this does NOT solve the problem.
5. I have done an asset check, which I will attach at the bottom of this message.
6. An attempt to restore my system to a state before the re-installation proved futile as the game itself now refused to start up. Undo-ing the restoring has led me to being able to play the game again but still not load that darn file.
7. I have had no CTDs while playing this file, it only started acting up after the re-installation.
This annoys me greatly, as if I understand it correctly, this is merely in place to prevent cheating from occuring. That's great, because when I play hotseat, where I'm with my friends or roleplaying on my own, I really need measures in place to prevent some malicious person, such as myself, hacking the file in order to win (yay, I beat myself!). Not to mention, that a multiplayer game I started before I re-installed, loads fine, and surely this is where the "protection" thing should be strongest.
I really would appreciate any help at this point and also hope that something is done by the developers to fix this problem. Interestingly enough, it is not the only time I have come accross this. When I tried transferring another hotseat game from one of my computers to another, I got the same error. However then, I could still continue playing on the old computer, while here I cannot play at all! Grr!
Once again, many thanks.
http://forums.civfanatics.com/attachment.php?attachmentid=118848&stc=1&d=1141762336