Description Of The Issue: This error means that something is going wrong with the code on your site and something is preventing WordPress from being able to connect to its MySQL database.
What Causes the WordPress Missing MySQL Extension Error:
1. You’re Using an Outdated Version of WordPress with PHP 7
If you’re using a very old version of WordPress with a modern version of PHP, you might encounter this error because PHP 7.0 deprecated the MySQL extension in favor of MySQLi. That is, PHP 7+ no longer includes the MySQL extension that WordPress is looking for. Modern versions of WordPress will instead use the newer PDO_MySQL or MySQLi extensions. However, older versions of WordPress (below version 3.9) might cause this problem.
2. You’re Using PHP 5.6 or Lower but the Extension Is Missing or Improperly Configured
The other likely cause is that you are using PHP 5.6 (before the MySQL extension was deprecated), but the extension is either missing or improperly configured.
Solutions to fix the issue
Step 1: Log in to your control panel.
Step 2: Check the PHP version which you are using currently.
Step 3: If you are using the PHP version below 7.3 updates it to either 7.4 or 8.
Step 4: Check the WordPress version which you are using currently.
Step 5: Check whether the MySql Extension is installed properly or not.
