What could be causing the Internal Server Error when trying to use mod_rewrite in PHP?

The Internal Server Error when trying to use mod_rewrite in PHP could be caused by incorrect configuration in the .htaccess file or server misconfiguration. To solve this issue, check the .htaccess file for any syntax errors or misconfigurations, ensure that mod_rewrite is enabled on the server, and verify that the RewriteEngine directive is set to on.

RewriteEngine On
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]