Sharing the effect

Sharing the effect

my problem is :
If I load 2 models ( the same model zombie ) and give them the same effect I got the following error :
        for(int i =0 ; i<2 ; i++)
        {
            dwarfModel[i].model = Content.Load<Model>("Models//dwarf//dwarfmodel");
            dwarfModel[i].effect = Content.Load<Effect>("Models//dwarf//skinFX");
            dwarfModel[i].setEffect(camera , game);
            dwarfModel[i].setModelAnimationStatus(game);
            dwarfModel[i].intializeChrachterController(new Vector3(0, 0, 0), 20, 10, 2000, 2000, 80, 40);

            space.Add(dwarfModel[i].chrachterController);

            dwarfModels.Add(dwarfModel);
        }
enter code here