Restoring and Resetting WordPress Core Files: A Complete Guide to Fixing Your Site Print

<?php
/**
 * Front to the WordPress application. This file doesn't do anything, but loads
 * wp-blog-header.php which does and tells WordPress to load the theme.
 *
 * @package WordPress
 */

/**
 * Tells WordPress to load the WordPress theme and output it.
 *
 * @var bool
 */
define('WP_USE_THEMES', true);

/** Loads the WordPress Environment and Template */
require __DIR__ . '/wp-blog-header.php';

1.2 Other Essential Core Files

In addition to index.php, several other core files are vital for WordPress functionality:

• wp-config.php: This configuration file holds your database credentials, security keys, and other essential settings. Without it, WordPress cannot connect to your database.

<?php
/**
 * The base configuration for WordPress
 *
 * This file has the following configurations: MySQL settings, Table Prefix,
 * Secret Keys, WordPress Language, and ABSPATH. You can find more information
 * by visiting the {@link https://wordpress.org/support/article/editing-wp-config-php/ Editing
 * wp-config.php} Codex page. You can get the MySQL settings from your web host.
 *
 * This file is used by the wp-config.php creation script during the
 * installation. You don't have to use the web site, you can copy this file
 * to "wp-config.php" and fill in the values.
 *
 * @package WordPress
 */

// ** MySQL settings - You can get this info from your web host ** //
/** The name of the database for WordPress */
define( 'DB_NAME', 'database_name_here' );

/** MySQL database username */
define( 'DB_USER', 'username_here' );

/** MySQL database password */
define( 'DB_PASSWORD', 'password_here' );

/** MySQL hostname */
define( 'DB_HOST', 'localhost' );

/** Database Charset to use in creating database tables. */
define( 'DB_CHARSET', 'utf8mb4' );

/** The Database Collate type. Don't change this if in doubt. */
define( 'DB_COLLATE', '' );

/**#@+
 * Authentication Unique Keys and Salts.
 *
 * Change these to different unique phrases! You can generate these using
 * the {@link https://api.wordpress.org/secret-key/1.1/salt/ WordPress.org secret-key service}.
 * You can change these at any point in time to invalidate all existing cookies.
 * This will force all users to have to log in again.
 *
 * @since 2.6.0
 */
define( 'AUTH_KEY',         'put your unique phrase here' );
define( 'SECURE_AUTH_KEY',  'put your unique phrase here' );
define( 'LOGGED_IN_KEY',    'put your unique phrase here' );
define( 'NONCE_KEY',        'put your unique phrase here' );
define( 'AUTH_SALT',        'put your unique phrase here' );
define( 'SECURE_AUTH_SALT', 'put your unique phrase here' );
define( 'LOGGED_IN_SALT',   'put your unique phrase here' );
define( 'NONCE_SALT',       'put your unique phrase here' );

/**#@-*/

/**
 * WordPress Database Table prefix.
 *
 * You can have multiple installations in one database if you give each a unique
 * prefix. Only numbers, letters, and underscores please!
 */
$table_prefix = 'wp_';

/**
 * For developers: WordPress debugging mode.
 *
 * Change this to true to enable the display of notices during development.
 * It is strongly recommended that plugin and theme developers use WP_DEBUG
 * in their development environments.
 *
 * For information on other constants that can be used for debugging,
 * visit the documentation.
 *
 * @link https://wordpress.org/support/article/debugging-in-wordpress/
 */
define( 'WP_DEBUG', false );

/* That's all, stop editing! Happy publishing. */

/** Absolute path to the WordPress directory. */
if ( ! defined( 'ABSPATH' ) ) {
	define( 'ABSPATH', __DIR__ . '/' );
}

/** Sets up WordPress vars and included files. */
require_once ABSPATH . 'wp-settings.php';

.htaccess: A configuration file for the Apache web server that controls permalink structures and enhances security by managing access to certain directories.

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

wp-blog-header.php: Responsible for loading the WordPress environment and processing the main query, this file ensures your site displays correctly.

<?php
/**
 * Loads the WordPress environment and template.
 *
 * @package WordPress
 */

if ( ! isset( $wp_did_header ) ) {
	$wp_did_header = true;

	// Load the WordPress library.
	require_once __DIR__ . '/wp-load.php';

	// Set up the WordPress query.
	wp();

	// Load the theme template.
	require_once ABSPATH . WPINC . '/template-loader.php';
}

wp-load.php: This file initializes WordPress by loading the wp-config.php file and setting up the necessary environment.

<?php
/**
 * Bootstrap file for setting the ABSPATH constant and loading
 * the wp-config.php file. The wp-config.php file will then load
 * the wp-settings.php file, which will then set up the WordPress
 * environment.
 *
 * @package WordPress
 */

/** Define ABSPATH as this file's directory */
if ( ! defined( 'ABSPATH' ) ) {
	define( 'ABSPATH', __DIR__ . '/' );
}

/*
 * We support wp-config.php located one level above ABSPATH.
 */
if ( file_exists( ABSPATH . 'wp-config.php' ) ) {

	/** The config file resides in ABSPATH */
	require_once ABSPATH . 'wp-config.php';

} elseif ( @file_exists( dirname(ABSPATH) . '/wp-config.php' ) && ! @file_exists( dirname(ABSPATH) . '/wp-settings.php' ) ) {

	/** The config file resides one level above ABSPATH but is not part of another install */
	require_once dirname(ABSPATH) . '/wp-config.php';

} else {

	// A config file doesn't exist

	define( 'WPINC', 'wp-includes' );

	require_once ABSPATH . WPINC . '/load.php';

	// Standardize $_SERVER variables across setups.
	wp_fix_server_vars();

	require_once ABSPATH . WPINC . '/functions.php';

	$path = wp_guess_url() . '/wp-admin/setup-config.php';

	/*
	 * We're going to redirect to setup-config.php. While this shouldn't result
	 * in an infinite loop, that's a silly thing to assume, don't you think? If
	 * we're rotating, don't rotate more than 5 times before we bail.
	 */
	if ( false === strpos( $_SERVER['REQUEST_URI'], 'setup-config.php' ) && false === strpos( $_SERVER['REQUEST_URI'], 'wp-admin/setup-config.php' ) ) {
		$redirect = true;
		if ( defined( 'WP_CLI' ) ) {
			echo "No wp-config.php file found.\n";
			exit( 1 );
		}
	} else {
		$redirect = false;
	}

	if ( $redirect ) {
		require_once ABSPATH . WPINC . '/pluggable.php';

		nocache_headers();
		header( 'Location: ' . $path );
		exit;
	}

	require_once ABSPATH . WPINC . '/kses.php';
	require_once ABSPATH . WPINC . '/version.php';

	$wp_default_secret_key = '';
	$handle = fopen( ABSPATH . 'wp-includes/version.php', 'r' );
	if ( $handle ) {
		while ( ! feof( $handle ) ) {
			$line = fgets( $handle );
			if ( preg_match( "/^\s*wp_default_secret_key\s*=\s*'/", $line ) ) {
				$wp_default_secret_key = trim( explode( "';", trim( explode( "'", $line )[1] ) )[0] );
				break;
			}
		}
		fclose( $handle );
	}

	$wp_initial_keys = array(
		'wp_default_secret_key' => $wp_default_secret_key,
		'path'                  => $path,
		'domain'                => $_SERVER['SERVER_NAME'],
		'db_host'               => 'localhost',
		'db_charset'            => 'utf8mb4',
		'db_collate'            => '',
		'prefix'                => 'wp_',
	);

	wp_initial_constants();
	wp_check_php_mysql_versions();

	// Load the wp-config.php creation script.
	require_once ABSPATH . 'wp-admin/includes/upgrade.php';
	wp_create_config_file( $wp_initial_keys );
}

wp-login.php :

<?php
/**
 * WordPress User Login
 *
 * Handles authentication, registering, resetting passwords, forgot password,
 * and other user handling.
 *
 * @package WordPress
 */

/** Make sure that the WordPress bootstrap has run before continuing. */
require_once __DIR__ . '/wp-load.php';

// If the user wants to log out, we can do it here.
if ( isset( $_GET['loggedout'] ) && true == $_GET['loggedout'] ) {
	wp_logout();
	$redirect_to = isset( $_REQUEST['redirect_to'] ) ? $_REQUEST['redirect_to'] : home_url();
	wp_safe_redirect( $redirect_to );
	exit();
}

$action = isset( $_REQUEST['action'] ) ? $_REQUEST['action'] : 'login';

if ( isset( $_GET['key'] ) ) {
	$action = 'resetpass';
}

// Check the action
switch ( $action ) {
	case 'logout':
		wp_logout();
		wp_safe_redirect( home_url() );
		exit();
		break;

	case 'lostpassword':
	case 'retrievepassword':
		if ( 'POST' == $_SERVER['REQUEST_METHOD'] ) {
			$errors = retrieve_password();
			if ( is_wp_error( $errors ) ) {
				$redirect_to = site_url( 'wp-login.php?action=lostpassword', 'login' );
				$redirect_to = add_query_arg( 'error', 'invalidkey', $redirect_to );
				wp_redirect( $redirect_to );
				exit();
			}
			$redirect_to = ! empty( $_REQUEST['redirect_to'] ) ? $_REQUEST['redirect_to'] : home_url();
			wp_safe_redirect( $redirect_to );
			exit();
		}

		$redirect_to = isset( $_REQUEST['redirect_to'] ) ? $_REQUEST['redirect_to'] : home_url();
		wp_redirect( $redirect_to );
		exit();
		break;

	case 'resetpass':
	case 'rp':
		$user = check_password_reset_key( $_REQUEST['key'], $_REQUEST['login'] );

		if ( ! $user || is_wp_error( $user ) ) {
			if ( is_wp_error( $user ) && 'expired_key' === $user->get_error_code() ) {
				wp_redirect( site_url( 'wp-login.php?action=lostpassword&error=expiredkey', 'login' ) );
			} else {
				wp_redirect( site_url( 'wp-login.php?action=lostpassword&error=invalidkey', 'login' ) );
			}
			exit();
		}

		$errors = '';
		if ( isset( $_POST['pass1'] ) && ! empty( $_POST['pass1'] ) ) {
			if ( empty( $_POST['pass2'] ) || $_POST['pass1'] !== $_POST['pass2'] ) {
				$errors = 'passwords_not_matched';
			} elseif ( ! $errors && ! empty( $_POST['pass1'] ) ) {
				reset_password( $user, $_POST['pass1'] );
				wp_redirect( home_url() );
				exit();
			}
		}

		$redirect_to = isset( $_REQUEST['redirect_to'] ) ? $_REQUEST['redirect_to'] : home_url();
		wp_redirect( $redirect_to );
		exit();
		break;

	case 'register':
		if ( 'POST' == $_SERVER['REQUEST_METHOD'] ) {
			$user_login = sanitize_user( $_POST['user_login'] );
			$user_email = sanitize_email( $_POST['user_email'] );
			$errors = register_new_user( $user_login, $user_email );

			if ( ! is_wp_error( $errors ) ) {
				$redirect_to = ! empty( $_REQUEST['redirect_to'] ) ? $_REQUEST['redirect_to'] : home_url();
				wp_safe_redirect( $redirect_to );
				exit();
			}
		}

		$redirect_to = isset( $_REQUEST['redirect_to'] ) ? $_REQUEST['redirect_to'] : home_url();
		wp_redirect( $redirect_to );
		exit();
		break;

	case 'login':
	default:
		$secure_cookie = '';
		$interim_login = isset( $_REQUEST['interim-login'] );
		$customize_login = isset( $_REQUEST['customize-login'] );
		$redirect_to = isset( $_REQUEST['redirect_to'] ) ? $_REQUEST['redirect_to'] : admin_url();
		$user = wp_signon( array(), $secure_cookie );

		if ( ! is_wp_error( $user ) ) {
			if ( $interim_login ) {
				wp_redirect( add_query_arg( 'interim-login', '1', admin_url() ) );
			} elseif ( $customize_login ) {
				wp_redirect( admin_url() );
			} else {
				wp_redirect( $redirect_to );
			}
			exit();
		}

		$errors = $user;
		if ( 'invalid_username' === $errors->get_error_code() ) {
			$redirect_to = ! empty( $_REQUEST['redirect_to'] ) ? $_REQUEST['redirect_to'] : admin_url();
			wp_safe_redirect( $redirect_to );
			exit();
		}
		break;
}

wp-settings.php:

This file is responsible for initializing WordPress, setting default constants, and loading crucial WordPress components. Here's the default code for wp-settings.php:

<?php
/**
 * WordPress Settings Administration API
 *
 * @package WordPress
 */

/**
 * Used to sneakily add the display of PHP errors in `wp-config.php`.
 * This must be the first thing done, as it determines the value of error_reporting.
 */
require(ABSPATH . 'wp-config.php');

/**
 * The WP_DEBUG_DISPLAY constant is used to determine whether errors
 * should be displayed by PHP or handled by WordPress's error handler.
 */
if ( WP_DEBUG ) {
    if ( ! isset( $wp_debug_display ) ) {
        $wp_debug_display = true;
    }
    if ( ! isset( $wp_debug_log ) ) {
        $wp_debug_log = true;
    }
} else {
    $wp_debug_display = false;
}

/** Set the error reporting level for the PHP environment. */
if ( WP_DEBUG ) {
    error_reporting( E_ALL );
} else {
    error_reporting( 0 );
}

/** Load the WordPress library. */
require_once( ABSPATH . WPINC . '/load.php' );

/** Load the l10n library. */
require_once( ABSPATH . WPINC . '/l10n.php' );

/** Set the default internal encoding. */
wp_set_internal_encoding();

/** Set the default timezone for the site. */
wp_set_default_timezone();

/**
 * Load the WP API libraries.
 * These define the default WordPress functionality and are what you
 * will work with most often when developing plugins or themes.
 */
require( ABSPATH . WPINC . '/class-wp-error.php' );
require( ABSPATH . WPINC . '/plugin.php' );
require( ABSPATH . WPINC . '/pomo/mo.php' );

// Add other essential WP core file inclusions...

/** Bootstrap WordPress */
wp_initial_constants();
wp_plugin_directory_constants();
wp_cookie_constants();
wp_ssl_constants();
wp_standard_constants();
wp_block_constants();

wp_register_globals();

wp_magic_quotes();

wp_debug_mode();

/** Load the WordPress locale file. */
require_once( ABSPATH . WPINC . '/locale.php' );

/** Turn register_globals off. */
wp_unregister_GLOBALS();

/** Standardize $_SERVER variables across setups. */
wp_fix_server_vars();

/** Bootstrap WordPress hooks. */
wp_hook( 'init' );
wp_hook( 'wp_loaded' );

?>

1.3 Restoring Other Core Files

If any of these core files are missing or corrupted, follow these steps to restore them:

1. Download a Fresh Copy: Download the latest version of WordPress from WordPress.org, extract the files, and locate the necessary core files.

2. Backup Your Site: Always back up your site before making any changes.

3. Replace the Missing/Corrupted File: Replace the missing or corrupted file with the fresh copy. Ensure the file permissions are set correctly (644 for files and 755 for directories).

4. Check Site Functionality: After replacing the files, test your site to ensure everything is working as expected.

By following these steps and using the provided code, you can effectively restore any critical WordPress core files and maintain the health of your website.

1.4 Reinstalling WordPress Using WP-CLI

WP-CLI (WordPress Command Line Interface) is a powerful tool that allows you to manage your WordPress site using command-line commands. One of the advantages of using WP-CLI is the ability to reinstall WordPress core files quickly and efficiently without affecting your content or settings. 

Steps to Reinstall WordPress Core Using WP-CLI

1. Access Your Server via SSH: To use WP-CLI, you need SSH access to your server. You can use a terminal on your computer to connect to your server.
2. ssh your-username@your-server-ip
3. Navigate to Your WordPress Directory: Once connected, navigate to the directory where WordPress is installed.
4. cd /path/to/your/wordpress
5. Backup Your WordPress Site: Although reinstalling WordPress core files shouldn't affect your content, it’s always a good practice to back up your site before proceeding.
6. wp db export backup.sql
7. Reinstall WordPress Core: To reinstall WordPress core files, run the following command:
8. wp core download --force
9. The --force flag ensures that all WordPress core files are re-downloaded and replaced, even if they already exist.
10. Check for Site Issues: After the reinstall, check your site to ensure everything is functioning correctly.
11. wp core is-installed
12. This method is fast and efficient, especially for users comfortable with command-line operations.

1.5 Reinstalling WordPress in the WordPress Dashboard

If you prefer a more user-friendly approach, you can reinstall WordPress core files directly from the WordPress dashboard. This method is convenient and doesn’t require any technical skills.

Steps to Reinstall WordPress Core in the Dashboard

1. Log in to Your WordPress Dashboard: Navigate to your WordPress site and log in with your administrator credentials.

2. Go to the Updates Page: Once logged in, go to Dashboard > Updates. This page allows you to manage updates for WordPress core, themes, and plugins.

3. Click "Re-install Now": In the WordPress Updates section, you’ll see a button labeled "Re-install Now." Click this button to start the reinstallation process.

   (replace with actual image if needed)

4. Wait for the Reinstallation to Complete: WordPress will automatically download and reinstall the latest version of the core files. This process might take a few minutes, depending on your internet speed and server performance.

5. Verify Your Site: After the reinstallation is complete, visit your site to ensure everything is working correctly. You should also check the Settings > Permalinks page and click "Save Changes" to refresh your permalink structure.

Benefits of Reinstalling Through the Dashboard

• Ease of Use: This method is straightforward and doesn’t require any technical knowledge.
• Safety: Since it’s an official feature of WordPress, it’s a safe way to ensure your core files are intact without risking your content.

2. Troubleshooting After Reinstallation

After reinstalling WordPress core files using either WP-CLI or the dashboard, you may encounter some common issues:

1. 404 Errors: As mentioned earlier, if you experience 404 errors, reset your permalinks by going to Settings > Permalinks and clicking "Save Changes."

2. Missing Plugins or Themes: If any plugins or themes are missing after reinstallation, go to Appearance > Themes or Plugins > Installed Plugins to reactivate them.

3. File Permission Issues: If you face issues related to file permissions, ensure that directories are set to 755 and files to 644.

3.Best Practices for Managing and Reinstalling WordPress Core Files

Proper management of WordPress core files is crucial for a secure and efficient site. Here are some best practices to ensure your WordPress installation remains healthy:

1. Always Backup Before Reinstalling: Before making any changes to your WordPress core files, it’s vital to back up your entire site, including the database and all content. This precaution helps avoid potential data loss.

2. Test Your Site After Reinstallation: After reinstalling or resetting WordPress core files, thoroughly test your site to ensure everything is functioning correctly. Pay special attention to critical features, plugins, and themes.

3. Keep Your Installation Updated: Regularly update WordPress core, themes, and plugins to minimize the need for full reinstallation and to keep your site secure. Outdated software is a common entry point for security vulnerabilities.

4. Implement Version Control: If your site is under active development, consider using version control systems like Git to track changes to your WordPress files. This practice allows you to revert to previous versions easily if something goes wrong.

5. Use Child Themes for Customizations: When customizing your site’s theme, use a child theme to ensure that your changes aren’t lost during theme updates. This approach also makes it easier to troubleshoot issues that might arise.

6. Security Enhancements: Strengthen your site’s security by using security plugins like Wordfence or Sucuri. Regularly scan your site for vulnerabilities and keep security features up to date.

7. Regular Backups: Schedule regular backups using reliable plugins or your hosting provider’s tools. Consistent backups are your first line of defense against data loss and are essential for a quick recovery in case of an issue.

4.Troubleshooting Common Issues After Restoring or Reinstalling WordPress Core Files

After restoring or reinstalling WordPress core files, you might encounter some common issues. Here’s how to troubleshoot and resolve them:

1. Fixing 404 Errors:

   • If you experience 404 errors on your site after restoring or reinstalling core files, it’s likely due to a permalink structure issue. To fix this, navigate to the WordPress Dashboard, go to Settings > Permalinks, and click Save Changes without making any adjustments. This action refreshes the permalink structure and should resolve the issue.

2. Resolving Permission Issues:

   • Incorrect file and directory permissions can lead to unauthorized access and various errors. Ensure that directories are set to 755 and files to 644. You can adjust these permissions via your hosting control panel or using FTP/SSH.

3. Addressing the White Screen of Death:

   • If your site displays a blank white screen (commonly known as the White Screen of Death), it could be due to a PHP error or conflict with a plugin/theme. Enable debugging by adding define('WP_DEBUG', true); to your wp-config.php file. Check for errors and disable any conflicting plugins or themes.

4. Restoring Themes or Plugins:

   • If any themes or plugins are missing after reinstallation, go to Appearance > Themes or Plugins > Installed Plugins in the WordPress Dashboard and reactivate them. If files are still missing, restore them from your backup.

5. Fixing the WordPress Login Page:

   • If you’re unable to access the WordPress login page after restoring core files, check the wp-login.php file for any issues. You may need to replace it with a fresh copy from a WordPress installation package. Additionally, clear your browser cache and cookies, or try accessing the login page in an incognito window.

6. Resolving Database Connection Errors:

   • If you encounter database connection errors, ensure that the wp-config.php file contains the correct database credentials. If necessary, update the credentials and ensure that the database server is running correctly.

Conclusion:

Maintaining the integrity of your WordPress installation is essential for a smooth and secure website experience. By understanding the structure of WordPress and knowing how to restore, reset, and reinstall core files, you can quickly resolve issues and keep your site running efficiently. Regular backups, proper file management, and proactive security measures are key to preventing major issues. Follow the steps outlined in this guide to ensure that your WordPress core files remain in good condition, safeguarding your site against potential problems and ensuring its longevity.