WordPress Toolkit Hotlinking Protection doesn’t work correctly with mod_pagespeed

Symptoms

• WordPress Toolkit Hotlinking Protection is enabled on the WordPress instance. Going to Domains > example.com > WordPress instance > Check Security > Hotlink protection is enabled.

• A caching mechanism is enabled. I.E.: native WordPress plugins, memcached, Google PageSpeed Insights, etc.

• An image is uploaded into httpdocs/wp-content/uploads folder path:

  

• However, accessing directly the image from httpdocs/wp-content/uploads folder shows the Hotlinking Protection image instead of the original file:

  

Cause

Cached files are loaded instead of the original files.

This is WordPress Toolkit extension bug #EXTWPTOOLK-2675 which will be fixed in future updates.

Resolution

As a workaround, disable Hotlinking Protection:

1. Log in to Plesk GUI

2. Go to Domains > example.com > WordPress Instance > Check Security > Disable Hotlink protection

3. Disable/uninstall any caching mechanism enabled and present for the WordPress website (I.E.: WordPress plugins, memcached, Google PageSpeed Insights, etc).

   Note: in some cases disabling all WordPress plugins and then re-activating both plugins and Hotlink protection fixes the issue.