Ensure that the 4GB patch is installed
- Download the 4GB patch here.
- Unpack the .zip file with Winzip/WinRar
- Open 4gb_patch.exe
- Locate the OMSI.exe in the OMSI installation directory (usually C:/Program Files(x86)/Steam/steamapps/common/OMSI 2)
- Select the OMSI.exe and confirm with Open
Reinstall the Addon
If you have problems with an OMSI Add-On, reinstall it first.
- In Steam, right-click OMSI 2 -> Settings -> DLC. You should see a list of OMSI DLCs.
- Uncheck the problematic DLC in the list
- Wait for the DLC to uninstall
- Restart Steam by closing and reopening it
- Navigate back to OMSI 2 -> Settings -> DLC and select the DLC you previously unchecked
- Wait for the DLC to download and see if the addon works as expected
Verify OMSI via Steam
If reinstalling the DLC hasn't resolved the issue, you might need to verify the game files. Follow Steams guide here to complete this.