The browser could not reach the server at all.
WHAT IT MEANS
No response. This is a network-level problem rather than a website problem.
CHECK WHETHER IT IS ONLY YOU
Test from mobile data with wifi off.
If it works there, your IP address is blocked by the firewall. This is the most common cause.
WHY YOU MIGHT BE BLOCKED
Several failed cPanel, FTP or email logins A mail client on a phone retrying an old password after you changed it Security software on your machine behaving like a scanner
GETTING UNBLOCKED
Open a ticket from the Client Area, or email from mobile data, quoting your address from whatismyip.com.
IF IT AFFECTS EVERYONE
Check whether the domain resolves. A DNS lookup tells you.
Check Client Area > Network Issues for a posted incident.
Check whether the hosting is suspended.
THE RECURRING BLOCK
If a block returns within hours of being lifted, a device is still using an old password. Check every phone and mail client, including ones you rarely use.