MainDBException error in Plesk

This article applies to 123-reg servers.

This article will explain what to do if you get a MainDBException error in Plesk Panel.

The below error normally affects Windows servers, and you should look in the following file to see if port=8306 and is referencing the right file paths:

\Plesk\MySQL\Data\my.ini

Check Windows Firewall is not causing the issue by turning each one (or all) off and try Plesk, check if the Plesk SQL Service service can start/restart via Services.msc. Also check the third tab along to see if Plesk MySQL Server is ticked (under venet0).

ERROR: PleskMainDBException
No connection could be made because the target machine actively refused it.

0: common_func.php3:619
reconnect()
1: common_func.php3:582
db_connect()
2: auth.php3:146
ERROR: PleskMainDBException
No connection could be made because the target machine actively refused it.

0: common_func.php3:619
reconnect()
1: common_func.php3:582
db_connect()
2: auth.php3:146

If you get:

ERROR: PleskMainDBException MySQL query failed: Table 'psa.skins' doesn't exist

Check the directive in the my.cnf file on the server lower_case_table_names = 1

The Plesk PSA database uses table names that start with a capital letter. With the above directive set to 1 (enabled) any queries are converted to lower case. As MySQL is case sensitive, this causes Plesk to look for a table called skins not Skins. Which causes the failure.

To fix it: Disable the directive in the my.cnf file, restart the server and check the Plesk panel is up and running normally now.