This is one of the common backup errors produced when the maximum number of  connections to the database is surpassed – after which this message is thrown “Failed to connect to database: User admin already has more than ‘max_user_connections’ active connections

In such a situation, unless any of the previously active connection is closed, no more connections can be established with the database. This may happen at occasions when there are too many requests made to the database OR a certain script consistently request for too many connections at any given point of time.

How to troubleshoot the backup error : Failed to connect to database?

Step 1 : RDP into the windows server.

Step 2 : Edit the file C:\Program Files\Parallels\Plesk\MySQL\Data\my.ini

Step 3 : Check the settings max_user_connections and increase the value or better remove the max_user_connections parameter and mysql default settings will be applied. This is how the file looks like :

my.ini screen grab