what computers are you running? My MacBook pro restarts too often and I just got tired of losing stuff so I stopped rendering anything until I can figure it out and replace it. Was told by a supposed "Mac Expert" that it is either the GPU or Hard Drive which leaves me open for a lot of expensive trial and error.Argh. Hate when that happens. In my case I generally left something rendering overnight and get up in the morning to find Studio sitting there with a blank viewport. The computer restarts. The program restarts. But the render certainly doesn't.