Microsoft has released a minor Windows 10 update package but necessary for users of Windows 10 Technical Preview. This update will fix blue screen error for users had upgraded to the build 9879 through “Fast Ring” feature a few weeks ago. “Fast Ring” is a very quick update mode of Windows 10 Technical Preview so users will experience the latest changes from Microsoft quickly, but it is not stable as the “Slow Ring” mode that always slow but more safer. You can switch between “Fast Ring” and “Slow Ring” can be done by: PC Settings > Update and recovery > Preview builds.

Source: Microsoft Twitter