Open the 4gb_patch.zip with 7zip instead of winrar, it's an old steam bug. If you already have the 4gb_patch but you extracted it from winrar, just replace it with the patch you extracted with 7zip instead. I did it and it worked!
Just download the regular old 4gb_patch from the website but open the .zip file with 7zip instead of winrar.
_TheNick_
joined
This member has provided no bio about themself...