My domain and business email hosting ISP today returned this error message when I tried to log in as usual (to check business emails).
I just blinked.
This server is currently not licensed. Please contact the server administrator. Other services available on this server such as web services are likely functioning normally. (Unknown License File Sum (has=,needed=20).)
Extraordinary, eh? Mind boggling?
With some difficulty, I found their tech support page. There were no customer alerts for this weekend. I left them a ticket. (That's what they call complaints.)
Fortunately, I use a different ISP for internet connection, and this kind of thing is precisely why I do not put all my internet needs in one basket!