I've had no problems with BtS from vanilla through patch 3.03, other than the occasional crash to desktop in the late game. However, after installing patch 3.13, I was unable to start the game.

I tried installing the patch from within the game (Advanced options) and manually. I tried rebooting after patching. I tried uninstalling the game completely (three times) and reinstalling. No luck.

So I'm back to version 3.03, but confused :confused: as to why the 3.13 patch breaks the game.

Any ideas?

That's an issue warez users are getting, basically the crack your using doesnt work properly. . :lol:

...basically the crack your using doesnt work properly. .

My Civ4, Warlords, and BtS are legal, licensed. I don't use unauthorized software.

My Civ4, Warlords, and BtS are legal, licensed. I don't use unauthorized software.
Please do this:
would anyone NOT using a cracked version please open the CivilizationIV.ini in your my documents/my games/Beyond the Sword directory and set all items that have log in their name to 1.
Then start the game, after it crashes zip all files in My Games\Beyond the Sword\Logs and upload those - if possible use this thread (http://forums.civfanatics.com/showthread.php?t=246038) to do so.
Also please post as many details on your system and version you can.