Title: Thumbnail error
Last modified: April 17, 2026

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# Thumbnail error

 *  [johnegg](https://wordpress.org/support/users/johnegg/)
 * (@johnegg)
 * [2 months, 1 week ago](https://wordpress.org/support/topic/thumbnail-error-10/)
 * Getting an error as it cant generate thumbs [https://ibb.co/Tqp9Fh0g](https://ibb.co/Tqp9Fh0g)
 * The page is behind a login is that the issue?
 * The page I need help with: _[[log in](https://login.wordpress.org/?redirect_to=https%3A%2F%2Fwordpress.org%2Fsupport%2Ftopic%2Fthumbnail-error-10%2F%3Foutput_format%3Dmd&locale=en_US)
   to see the link]_

Viewing 2 replies - 1 through 2 (of 2 total)

 *  Thread Starter [johnegg](https://wordpress.org/support/users/johnegg/)
 * (@johnegg)
 * [2 months ago](https://wordpress.org/support/topic/thumbnail-error-10/#post-18886539)
 * Any help here guys?
 *  Plugin Author [Sergio Comella](https://wordpress.org/support/users/panezio923/)
 * (@panezio923)
 * [2 months ago](https://wordpress.org/support/topic/thumbnail-error-10/#post-18887177)
 * Hi,
 * thank you for the patience.
 * To determine which scenario you’re in, verify these things:
    1. Are the PDF files publicly accessible? Open a PDF URL directly in an incognito/
       private browser window (not logged into WordPress). If it loads — thumbnails
       will work. If you get a login redirect or 403 — thumbnails will fail.
    2. What type of authentication protects the page?
    3. Check the browser console on the protected page Open DevTools → Console while
       logged out (or in incognito).
    4. Check the Network tab In DevTools → Network, filter by the .pdf extension and
       reload the page. Look at the Status column for each PDF request. Anything other
       than 200 means thumbnails won’t render.
 * The real risk is only if you have users who can see the page/gallery but whose
   session doesn’t grant access to the raw /wp-content/uploads/… PDF URLs — that
   depends on how your membership/auth plugin controls attachment access.
 * Let me know and we’ll solve it 🙂

Viewing 2 replies - 1 through 2 (of 2 total)

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to reply to this topic.

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 * 2 replies
 * 2 participants
 * Last reply from: [Sergio Comella](https://wordpress.org/support/users/panezio923/)
 * Last activity: [2 months ago](https://wordpress.org/support/topic/thumbnail-error-10/#post-18887177)
 * Status: not resolved