Symptoms
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WordPress admin dashboard is not displaying properly: layout is broken. css/js scripts are not loaded.
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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"
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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 WP Toolkit.
Resolution
Through WP Toolkit in Plesk:
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Go to Domains > example.com > WordPress > select affected WordPress instance > Security Status (Check Security in older WP Toolkit versions).
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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:
-
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);