https://www.bleepingcomputer.com/news/microsoft/windows-10-1903-blocked-for-kerberos-domain-connected-devices/ > Microsoft has now started blocking customers from installing the Windows 10 May 2019 Update on domain connected devices that use MIT Kerberos realms. > This comes on the heels of a previous announcement issued on July 25 saying that "devices connected to a domain that is configured to use MIT Kerberos realms will not start up or may continue to restart" after installing a recent cumulative update.