I have Start8 v1.56 running on Windows 8.1 x64 and it presents an apparently random problem:
When I start the computer, the whole desktop freezes even before the icons start to show. After some trial and error, I found out that I can bypass this crash by double clicking on the desktop area. However, a number of auto launching apps no longer launch automatically when this happens. But then I have access again to the desktop and I restart the computer.
Usually, after about 10 restart attempts, it finally starts normally without crashing.