Following could be the reason:

1. The website is under maintenance mode.
2. The hosting service has expired.
3. The website name might have been misspelled or doesn't exist in our server.
4. The hosting service has been suspended due to reporting of fraud / service overutilization /
    breach of terms and etc.

For site owner, you may contact us at +603-20584799 (Mon-Fri 0930 to 1830 GMT +8 hours) or Submit a Ticket to Support/Billing Department for further information.