How can one troubleshoot and fix a "Error 500" issue when using mod_rewrite in PHP?

When encountering an "Error 500" issue while using mod_rewrite in PHP, it is likely due to a misconfiguration in the .htaccess file or server settings. To troubleshoot and fix this issue, check the syntax of your mod_rewrite rules, ensure that the necessary modules are enabled in Apache, and verify that the file paths are correct.

<IfModule mod_rewrite.c>
    RewriteEngine On
    RewriteBase /
    RewriteRule ^index\.php$ - [L]
    RewriteCond %{REQUEST_FILENAME} !-f
    RewriteCond %{REQUEST_FILENAME} !-d
    RewriteRule . /index.php [L]
</IfModule>