If you have upgraded PHP on InterWorx 5.1.x to 5.6.x (yum update php -y) you may see this error: SQLSTATE[HY000] [2054] The server requested authentication method unknown to the client on line [..]
To fix this all you need to do is edit the MySQL configuration: nano /etc/my.cnf and change old-passwords=1 to old-passwords=0 and then restart MySQL: service mysqld restart.
