Windows 10 Update 25 th March 2018

[jer1956]

It looks like this update resets SMB1 to off in Windows Features. The symptoms are:-
No SMB1 server.
No SMB1 search via Network Discivery.
No SMB1 Client via IP and browser.
No SMB1 drive mapping.
So use Windows Features to turn it back on.

Also check Advanced Sharing. In All it may have turned Password Sharing back on.

None of this was announced. They are flipping settings for security reasons without saying so.