Site shows error: Your PHP installation appears to be missing the MySQL extension which is required by WordPress

Updated: 28 September 2026 · Applies to: Plesk Obsidian 18 with CloudLinux PHP Selector

On a Plesk server with CloudLinux, WordPress may report Your PHP installation appears to be missing the MySQL extension even though an extension called mysql or mysqli is enabled. The cause is usually the wrong combination of MySQL drivers in the CloudLinux PHP Selector.

Fix in the PHP Selector

1. In Plesk, open the subscription and go to the PHP Selector (or run selectorctl --list-extensions --version=8.3 as root).
2. Enable mysqlnd, nd_mysqli and nd_pdo_mysql.
3. Disable mysqli and pdo_mysql (the non-nd_ versions), which conflict with them.
4. Reload the site.

Also check

• The site uses the PHP version you changed: Websites & Domains › PHP in Plesk Obsidian.
• The PHP version is supported by your WordPress version (use PHP 8.3 or newer for WordPress 7.1). The old mysql extension of PHP 5 is not needed and does not exist in PHP 7 and newer.

Check from SSH

selectorctl --list-extensions --version=8.3 | grep -E "mysql"

A + in front of a name means enabled. After the change, nd_mysqli, nd_pdo_mysql and mysqlnd should have a +, and mysqli / pdo_mysql a -.