I decided to enroll in the Insider Preview program (slow ring) to receive the Windows 10 1903 update. It downloaded and installed without problem, but on rebooting my computer I simply get a black screen and a spinning circle. I left the computer over night, and then hard rebooted it a couple of times but same issue. I wound up booting to my Windows 10 Recovery disk and chose to do a System Restore to just before the 1903 update, and now everything works fine again. Has anyone else had this problem, and if so, have you found a fix?