A solution for broken thumbnails

The recent update has caused an issue whereby thumbnail images are not displayed correctly in gallery view, particularly on older installations. The update introduced two types of thumbnail: one for the gallery view (cached computed) and one for the actual image file (as a file). In many cases, the paths to the gallery image thumbnails are incorrectly formatted, missing a slash between the domain and the wp-content path. This issue is also sometimes observed at the end of the path.

This problem essentially consists of two distinct issues. Firstly, some very old installations have the gallery paths stored in the MySQL database without the necessary slashes at the beginning and end. These slashes must be added manually to the paths in the database to resolve the issue and ensure that the correct path is referenced.

Secondly, the latest update seems to have made the “full” and “thumbnail” metadata entries mandatory for the images in the gallery. It is unclear exactly when this change was introduced, but it now appears to be necessary for the correct display of thumbnails. While it is possible to regenerate thumbnails for all images, this results in the loss of custom thumbnail sizes, which can be problematic for users with a variety of custom image formats and sizes. Regenerating thumbnails resets all custom thumbnail dimensions, meaning users would have to recreate any custom sizes they have configured, which is time-consuming.

To resolve the issue, go to the gallery, select all the images and, from the ‘Bulk Actions’ drop-down menu, choose ‘Rotate Clockwise’. After waiting for this to complete, select ‘Rotate counterclockwise’. This will trigger the plugin to update the image metadata and add the missing entries. Once this is done, the thumbnails should appear correctly in gallery view.

Well, a quick workaround does the job for now, but maybe it’s time to look at those outdated data structures. After all, there are a lot of long-time users out there who’d probably appreciate it — unless they enjoy playing ‘Where’s the #&%$ Thumbnail?’ next time. Cheers and thanks for this brain teaser.