Update 2/28: At around 18% of the installation phase of the update, some devices are rebooting back into the previous build. After this happens 3 times, the next try should change the upgrade path and successfully update you to 18342.8. We appreciate your patience while we investigate the cause and get a fix out. UPDATE 2/27: Today we have released Windows 10 Insider Preview Build 18342.8 (19H1) t