Slayer's Part Correct. If you modified ONLY gta-vc.exe, then you can't install the patch. BTW, if you have New Vice City 2004 mod installed, DO NOT buy Starfish Sam villa OR the police station. It will cause your game to crash a lot. It happened to me. Also, If you have Tommy's Private Island installed, You might (at some time) see absolutely no peds or driving vehicles. DO NOT save the game, or the problem stay forever. I am not sure on how to fix it.