Mods are unofficial fan-made add-ons. Because they aren't created by the developer of the game, there might be compatibility or running problems, like in your case. The only thing that you can do, in this matter, is to make sure that you are properly installing the add-on and that the game version is compatible with the add-on. Also, it might be a good idea to check the GTAGarage website. There, you will be able to find more information about this mod that you want to use.