discussion Guide Plesk Fixing “Column Count of mysql.user is Wrong” Error During Plesk Backup (2025 Guide)

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🧩 Issue: MySQL User Table Error During Plesk Backup​

While performing a backup in Plesk Panel, you may encounter one of the following errors:

Connection to the database server failed: Column count of mysql.user is wrong.
Expected 42, found 39. Created with MySQL 50173, now running 50556.
Please use mysql_upgrade to fix this error.

or

Column count of mysql.user is wrong. Expected 45, found 48.
The table is probably corrupted.

These errors typically occur after a MySQL version upgrade when the mysql.user table structure becomes incompatible with the current server version.

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🛠️ Solution: Fix Compatibility Issues Using mysql_upgrade​

1. Connect to Your Server via SSH​

Log in to your server using the root user:

ssh root@server-ip

2. Run the mysql_upgrade Command​

Plesk uses the admin user for database management, and its password is stored in /etc/psa/.psa.shadow.
Run the following command to check and fix compatibility:

MYSQL_PWD=`cat /etc/psa/.psa.shadow` mysql_upgrade -uadmin -T --debug-check MySQL

3. If the Problem Persists, Use the --force Parameter​

If the first command doesn’t solve the issue, rerun it with the --force flag to apply upgrades forcibly:

MYSQL_PWD=`cat /etc/psa/.psa.shadow` mysql_upgrade -uadmin --force

4. Restart Plesk Services​

Once the upgrade is complete, restart the Plesk services:

service psa restart

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🔍 MySQL Version Compatibility Check​

You can verify database version differences via the Plesk interface:

Plesk Panel > Tools & Settings > Database Servers

Here, if your current MySQL/MariaDB version differs from the version used when the mysql.user table was originally created,
the mysql_upgrade command must be executed — otherwise, backups and database operations will continue to fail due to schema mismatches.

 

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If a problem occurs, you can open a ticket.