Hey i downloaded all of them and tried them one at a time but everytime everything is black but the supercross track/ HELP!

Hey i downloaded this and put it on mxs but i have it equiped but it isnt on my rider its just a plain helmet how do i fix this?? someone said about downloading the model but idk what they mean and if u find the download for this can u send it to me? that would help me alot thanks!!!