WordPress backend is loading without style

Question

My website WordPress backend is not loading with CSS….the frontend is working fine but once i try login to my wordpress admin the page load without any style .. I have reinstalled WordPress core file many time and i have try and added these (define( ‘CONCATENATE_SCRIPTS’, false ); define( ‘SCRIPT_DEBUG’, true ); in wp-config.php but problem still not fixed

the error in chrome consul is showing :

Refused to apply style from 'https://www.csm.school/wp-admin/load-styles.php?c=1&dir=ltr&load%5Bchunk_0%5D=dashicons,admin-bar,wp-pointer,site-health,common,forms,admin-menu,dashboard,list-tables,edit,revisions,media,themes,about,nav-m&load%5Bchunk_1%5D=enus,widgets,site-icon,l10n,buttons,wp-auth-check&ver=5.4.2' because its MIME type ('text/html') is not a supported stylesheet MIME type, and strict MIME checking is enabled.

Function.php :

<?php

// simple error trapping on screen
// Report simple running errors
error_reporting(E_ERROR | E_WARNING | E_PARSE);

// full errors
//  error_reporting(E_ALL);


/**
 * Customify functions and definitions
 *
 * @link    https://developer.wordpress.org/themes/basics/theme-functions/
 *
 * @package customify
 */

/**
 *  Same the hook `the_content`
 *
 * @TODO: do not effect content by plugins
 *
 * 8 WP_Embed:run_shortcode
 * 8 WP_Embed:autoembed
 * 10 wptexturize
 * 10 wpautop
 * 10 shortcode_unautop
 * 10 prepend_attachment
 * 10 wp_make_content_images_responsive
 * 11 capital_P_dangit
 * 11 do_shortcode
 * 20 convert_smilies
 */
global $wp_embed;
add_filter( 'customify_the_content', array( $wp_embed, 'run_shortcode' ), 8 );
add_filter( 'customify_the_content', array( $wp_embed, 'autoembed' ), 8 );
add_filter( 'customify_the_content', 'wptexturize' );
add_filter( 'customify_the_content', 'wpautop' );
add_filter( 'customify_the_content', 'shortcode_unautop' );
add_filter( 'customify_the_content', 'wp_make_content_images_responsive' );
add_filter( 'customify_the_content', 'capital_P_dangit' );
add_filter( 'customify_the_content', 'do_shortcode' );
add_filter( 'customify_the_content', 'convert_smilies' );


/**
 *  Same the hook `the_content` but not auto P
 *
 * @TODO: do not effect content by plugins
 *
 * 8 WP_Embed:run_shortcode
 * 8 WP_Embed:autoembed
 * 10 wptexturize
 * 10 shortcode_unautop
 * 10 prepend_attachment
 * 10 wp_make_content_images_responsive
 * 11 capital_P_dangit
 * 11 do_shortcode
 * 20 convert_smilies
 */
add_filter( 'customify_the_title', array( $wp_embed, 'run_shortcode' ), 8 );
add_filter( 'customify_the_title', array( $wp_embed, 'autoembed' ), 8 );
add_filter( 'customify_the_title', 'wptexturize' );
add_filter( 'customify_the_title', 'shortcode_unautop' );
add_filter( 'customify_the_title', 'wp_make_content_images_responsive' );
add_filter( 'customify_the_title', 'capital_P_dangit' );
add_filter( 'customify_the_title', 'do_shortcode' );
add_filter( 'customify_the_title', 'convert_smilies' );

// Include the main Customify class.
require_once get_template_directory() . '/inc/class-customify.php';

/**
 * Main instance of Customify.
 *
 * Returns the main instance of Customify.
 *
 * @return Customify
 */
function Customify() {
    // phpc:ignore WordPress.NamingConventions.ValidFunctionName.
    return Customify::get_instance();
}

Customify();

Load-style.php:

    <?php

/**
 * Disable error reporting
 *
 * Set this to error_reporting( -1 ) for debugging
 */
error_reporting( 0 );

/** Set ABSPATH for execution */
if ( ! defined( 'ABSPATH' ) ) {
    define( 'ABSPATH', dirname( __DIR__ ) . '/' );
}

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

require ABSPATH . 'wp-admin/includes/noop.php';
require ABSPATH . WPINC . '/script-loader.php';
require ABSPATH . WPINC . '/version.php';

$protocol = $_SERVER['SERVER_PROTOCOL'];
if ( ! in_array( $protocol, array( 'HTTP/1.1', 'HTTP/2', 'HTTP/2.0' ) ) ) {
    $protocol = 'HTTP/1.0';
}

$load = $_GET['load'];
if ( is_array( $load ) ) {
    ksort( $load );
    $load = implode( '', $load );
}

$load = preg_replace( '/[^a-z0-9,_-]+/i', '', $load );
$load = array_unique( explode( ',', $load ) );

if ( empty( $load ) ) {
    header( "$protocol 400 Bad Request" );
    exit;
}

$rtl            = ( isset( $_GET['dir'] ) && 'rtl' == $_GET['dir'] );
$expires_offset = 31536000; // 1 year.
$out            = '';

$wp_styles = new WP_Styles();
wp_default_styles( $wp_styles );

if ( isset( $_SERVER['HTTP_IF_NONE_MATCH'] ) && stripslashes( $_SERVER['HTTP_IF_NONE_MATCH'] ) === $wp_version ) {
    header( "$protocol 304 Not Modified" );
    exit();
}

foreach ( $load as $handle ) {
    if ( ! array_key_exists( $handle, $wp_styles->registered ) ) {
        continue;
    }

    $style = $wp_styles->registered[ $handle ];

    if ( empty( $style->src ) ) {
        continue;
    }

    $path = ABSPATH . $style->src;

    if ( $rtl && ! empty( $style->extra['rtl'] ) ) {
        // All default styles have fully independent RTL files.
        $path = str_replace( '.min.css', '-rtl.min.css', $path );
    }

    $content = get_file( $path ) . "\n";

    if ( strpos( $style->src, '/' . WPINC . '/css/' ) === 0 ) {
        $content = str_replace( '../images/', '../' . WPINC . '/images/', $content );
        $content = str_replace( '../js/tinymce/', '../' . WPINC . '/js/tinymce/', $content );
        $content = str_replace( '../fonts/', '../' . WPINC . '/fonts/', $content );
        $out    .= $content;
    } else {
        $out .= str_replace( '../images/', 'images/', $content );
    }
}

header( "Etag: $wp_version" );
header( 'Expires: ' . gmdate( 'D, d M Y H:i:s', time() + $expires_offset ) . ' GMT' );
header( "Cache-Control: public, max-age=$expires_offset" );

echo $out;
exit;

.Htaccess:

<FilesMatch index.php>
Order Allow,Deny
Allow from all
</FilesMatch>
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . index.php [L]
</IfModule>

Answer 1

The load-style.php URL you provided above is redirecting to the login form and this is why the inspector is complaining about a HTML response.

I tested this on a fresh installation and WordPress returns the styles even if you are logged off so you much have some .htaccess or PHP code redirecting the load-style.php file to the login form.

You have also removed a line of the core which tells the browser the PHP script is a CSS file, though I suspect Chrome would still parse it so long as the response was actually CSS, you should never do this and as such I would also recommend re-installing WordPress via Dashboard => Updates to get the core back to its correct state.

Answer 2

Probably some (cache) plugin does this in your admin

Add this in config.

define( 'CONCATENATE_SCRIPTS', false );