You may get the below phpMyAdmin error for a couple different reasons which could be related to upgrading PHP or possibly on a new installation of phpMyAdmin. The issue can be resolved easily by installing or upgrading mcrypt on your server.
Error:Cannot load mcrypt extension. Please check your PHP configuration.
If you receive this error simply login to your server, which in this case was a 5.2 CentOS server, and install or upgrade mcrypt using the yum package manager. The package that needs to be installed for mcrypt to work properly with phpMyAdmin is php-mcrypt.
- yum install php-mbstring //For Centos
- sudo install php-mbstring //For Ubuntu
The versions need to match as shown above so if they do not match this should be the first place to start troubleshooting.
sudo /etc/init.d/httpd restart
Finally, refresh to check its working.