I had the same issue as ridvan34 every time I installed the MySQL-plugin after changing the root password (which I usually do as soon as the mysql server is running). It drove me crazy and nobody seemed to have a solution...
This time I tried some very easy hints from the MyWebSQL-site:
For the file ‘config/auth.php’:
For the file ‘config/servers.php’:
$SERVER_LIST = array(
‘Localhost MySQL’ => array(
‘host’ => ‘localhost:3307’,
Since I'm still using the standard port I changed the "localhost:3307" to "localhost:3306".
After doing that I rebooted the server and was able to access MySQL via MyWebSQL again (with the new password)
I don't know whether the settings above were actually necessary at all but in my previous attempts to use the plugin I never succeeded - despite rebooting the server on a regular basis.
Just thought this experience could help.