What do i do when my Roblox Studio cant render objects?

All the sudden when i go on my other computer (the other was fine) i finish and go on my original computer and the same game i made (i opened in studio) heads were not loading, and to check that it wasnt my game, i draged in a person model, it it was the same; no shirts or pants, grey skin, no head mesh. So its either my computer or this studio, please help :)