Disable all other mods. Download the latest version (re-download even if you think it's the latest). Delete any modules/ folder and its contents that may exist in your mod folder. Follow the installation instructions again religiously. Verify the integrity of your game files via Steam. Then give it another go.
Then, if you still have a problem, please provide the file version.txt that the installer generates and places inside the default 'Historical Immersion Project' folder in your mod folder so that we know what you've actually installed and can help you.