error: DATABASE ERROR: CONNECTION FAILED!

==== Required information ====
- iRedMail version (check /etc/iredmail-release):
- Linux/BSD distribution name and version:
- Store mail accounts in which backend (LDAP/MySQL/PGSQL):
- Web server (Apache or Nginx):
- Manage mail accounts with iRedAdmin-Pro?
- Related log if you're reporting an issue:
======== Required information ====
- iRedMail version (check /etc/iredmail-release): 0.9.3
- Linux/BSD distribution name and version: OVH CentOS 7
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Web server (Apache or Nginx): Apache
- Manage mail accounts with iRedAdmin-Pro?
- Related log if you're reporting an issue:
====
Hello I get the following error with roundcubemail using IRedMail with CentOS 7:
http://imgur.com/1e46CgY
"DATABASE ERROR: CONNECTION FAILED!"
I am a bit of a noob to mail servers and was wondering what is causing this error.
Many Thanks
Joe