Following could be the reason:

1. The website is under maintenance mode.
2. The hosting service has expired.
3. 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 2058 4799 (Mon-Fri 0930 to 1830 GMT +8 hours) or Submit a Ticket to Support/Billing Department for further information.