i got the same message after i reinstalled the entire game, it still said Pak 0 was not a valid file of the previous version and could not me upgraded. i spent an hour and a half reinstalling
I think the problem is that someone challenged you and you took too long to respond. And are you sure you're putting the patch in the Main Folder and not trying to drop it straight into a pak file...
i think it's because of the downloaded version you haduninstall everything againbut go through program files and make sure everything is erased...maybe
i uninstalled my reinstall....i deleted every trace of the game except for screenshots and then i reinstalled it again..and i still get the same message about pak0 is not a valid version of the previous game and cannot be upgraded....it looks like i might as well retire from cod now
You're obviously doing something wrong, since it has worked for everyone else. Post screenies of everything you try to do and perhaps we can find the problem.
ok first thing: i reinstall the game to c/program files/call of duty. then i try the patch on the default path, doesnt work, i find the call of duty folder, try it, doesnt work. btw this is the patch .exe which is located on my desktop. here is what i get each time