Always launch the game via LaunchGTAIV.exe (as administrator) rather than through the Steam library once you've downgraded to avoid the launcher trying to "update" you back to the broken version!
Almost every major mod created between 2010 and 2020 was designed for 1.0.7.0. downgrade gta iv to 1.0.7.0
Copy your entire Grand Theft Auto IV folder to a safe location. If something goes wrong, you won’t have to redownload 20GB of data. Step 2: Use the GTA IV Downgrader Tool Always launch the game via LaunchGTAIV
