phpMyAdmin: CONNECTION FOR CONTROLUSER AS DEFINED IN YOUR CONFIGURATION FAILED
What is the cause of this error?
First, you have to make sure that your MySQL server is up and running. Since this is trivial and easy to determine, it is most likely not the cause of the error (also, other errors along this one are displayed in that case).
Second, have you recently changed your MySQL Server root password? If answer is YES, then this is the cause of the error / warning inside phpMyAdmin console. To fix the problem, simply edit your phpMyAdmin’s config-db.php file and setup the proper database password:
In Linux-based servers the file is usually located in:
/etc/phpmyadmin/config-db.php
or:
/etc/phpMyAdmin/config-db.php
Notice the camelCase difference in the above path names: /phpmyadmin/ and /phpMyAdmin/ are two different directories under Linux operating systems! Under Windows, directory names are not case-sensitive, so above paths will be the one and only (same) directory.
EXAMPLE CONTENT:
$dbuser='root';
$dbpass='password'; // set current password between quotes ' '
$basepath='';
$dbname='phpmyadmin';
$dbserver='';
$dbport='';
$dbtype='mysql';