Knowledge Base

WordPress admin dashboard is not displaying properly for a Plesk domain: css/js scripts are not loaded. Access forbidden by rule

Symptoms

WordPress admin dashboard is not displaying properly: layout is broken. css/js scripts are not loaded.

The following or similar error messages are shown in /var/www/vhosts/example.com/logs/proxy_error_log:

[error] 1938949#0: *7483 access forbidden by rule, client: 203.0.113.2, server: example.com, request: "GET /wp-admin/load-scripts.php?c=0&load%5B%5D=jquery-core,jquery-migrate,jquery-ui-core,jquery-ui-widget,jquery-ui-mouse,jquery-ui-resizable,jquery-ui-draggable,jquery-ui-but&load%5B%5D=ton,jquery-ui-position,jquery-ui-dialog,utils,moxiejs,plupload&ver=4.9.6 HTTP/2.0", host: "example.com", referrer: "https://example.com/wp-admin/update-core.php"

Browser DevTools (F12 in Google Chrome) > Network tab shows that load-styles.php file cannot be proceeded by a browser due to 403 error (Forbidden response).

Cause

Security settings in WordPress Toolkit.

Resolution

Through WordPress Toolkit in Plesk:

Log into Plesk.
Go to Domains > example.com > WordPress > select affected WordPress instance > Security Status (Check Security in older WordPress Toolkit versions).
Select Disable scripts concatenation for WordPress admin panel and click Revert.

Via wp-config.php file over SSH:

Connect to the server via SSH.
Open a file /var/www/vhosts/example.com/httpdocs/wp-config.php with a text editor.
Add the following record at the end of the file before the require_once directive:
```
define('CONCATENATE_SCRIPTS', false);
```

Via wp-config.php file through Plesk UI:

Log into Plesk.
Go to site’s document root in Domains > example.com > File Manager:
Add the following record at the end of the file before the require_once directive:
```
define('CONCATENATE_SCRIPTS', false);
```