If the event viewer error says "HTTP could not register URL" (typically after running SCU against all the utilities Hub, Announcer, etc)
You can fix it with netsh in CMD as admin.
%System32%\netsh.exe http add urlacl url=http://+:4020/
(where host\user is the machine name and local admin account running the WIN-911 services)
If running that command returns error 183 that means there's an existing reservation in the way. You can clear the path with:
then, re-run the original command above.