On the Mac OS platform, if you try to save at the same time as the autosave is running (like right after you close the rendering window) the program locks up and crashes. This was true for v6.0 as well.
I have excatly the same problem and my friend told me to reinstall, so I did and it’s working properly. Probably the was a software problem. Try it yourself and I hope it will help you as well live casino svergie