Environment:
- WordPress 5.4.1 multisite
- PHP 7.3
- Apache
Problem:
The draft preview of pages and posts works poorly on my main site. The other sites works just fine. The setup has a mother theme and all sites has their own child theme. Every other time (sometimes more) I’m greeted with the message: “Sorry, you are not allowed to preview drafts.”.
The message is outputed in wp-includes/revision.php:
<?php
/**
* Filters the latest content for preview from the post autosave.
*
* @since 2.7.0
* @access private
*/
function _show_post_preview() {
if ( isset( $_GET['preview_id'] ) && isset( $_GET['preview_nonce'] ) ) {
$id = (int) $_GET['preview_id'];
if ( false === wp_verify_nonce( $_GET['preview_nonce'], 'post_preview_' . $id ) ) {
wp_die( __( 'Sorry, you are not allowed to preview drafts.' ), 403 );
}
add_filter( 'the_preview', '_set_preview' );
}
}
Tried solutions to the problem (no luck so far):
- Flush permalinks
- Disable all plugins
- Switched to a child theme from another site on the multisite where the draft works.
- Check to see if site url and home url are the same in the databse.
- Cleared cache.
My .htaccess (nothing fancy):
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
# add a trailing slash to /wp-admin
RewriteRule ^([_0-9a-zA-Z-]+/)?wp-admin$ $1wp-admin/ [R=301,L]
RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(wp-(content|admin|includes).*) wp/$2 [L]
RewriteRule ^([_0-9a-zA-Z-]+/)?(.*\.php)$ wp/$2 [L]
RewriteRule . index.php [L]
Header set Access-Control-Allow-Origin "*"
I’m really scratching my head on this one. Any ideas what might be the problem? Based on the function outputing the message I recon it have something to do with the nonce? But why only on my main site?