Locate the folder named SmartSteamEmu_v1.4.3_for_L4D2 inside your game directory.
: This build often comes with a "Steamworksfix" enabled by default to allow multiplayer via Steam. Single Player Mode : Download Left 4 Dead 2 Build 4017680 DLCs M...
Copy all content from this folder and paste it into the main game root directory. Launch the game using SmartSteamLoader.exe to play offline. Locate the folder named SmartSteamEmu_v1