i was getting this message too but it went away when i added the new admx files to the domain.
Edit:
Spoke too soon. It made it to the logon screen and i entered credentials and then... same message "Why did my PC restart"
Restarted and got "just a moment" message for 15 min then restarted and... "Why did my PC restart"
i will try this: https://www.windowsmanagementexperts.com/osd-issue-with-windows-10-1703/osd-issue-with-windows-10-1703.htm next