Locked out of their computers, that is, don’t get any funny ideas. This Windows 10 bug, although not widespread, has affected some testers, not allowing them to log into their machines.

Build 10041 of the Windows 10 Technical Preview was [Only registered and activated users can see links. ] out last week, and the company soon followed that with a more stable [Only registered and activated users can see links. ] for users enrolled in the slow ring for the Windows Insider program.
Three different patches accompanied the second release, meant to fix feature, performance and security bugs in the preview operating system.

This brand new patch, known as [Only registered and activated users can see links. ] was released earlier today, and aims to fix issues that result in the user name and password box not to appear on the sign-in screen.
No one wants that, really.

Apparently this was flagged high enough to warrant a priority release from the company. The patch is now available for download, and it probably is a good idea to deploy it via Windows Update just to stay on the safe side.

Unless you want to take your chances with getting locked out of your Windows 10 installation.