Since version 5.3, WordPress will detect and scale down large image uploads automatically for optimization purposes.
For example, when you upload a 3000×4000 pixel image to your website, it will be resized to the default threshold values which is 2560px.
WordPress also marks the scaled-down images with
-scaled word at the end of the file URL. For example, a resized image URL will look like:
By default, Prevent Direct Access Gold protects your images and all its sizes based on the default file URL. Since the default scaled image URL stored under
_wp_attached_file is changed, our plugin cannot detect the scaled image and serve them correctly.
As a result, our current file protection method will lead to all sizes of the scaled images returning 404.
We’re addressing the issue in the upcoming version of our PDA Gold.
Temporary Solution: Disable the scaling
Currently, you can resolve the image protection issue by temporary disabling the WordPress scaling feature with the following code:
add_filter( 'big_image_size_threshold', '__return_false' );
We will be updating our official solution soon.