Wikimedia Bugzilla is closed!

Wikimedia migrated from Bugzilla to Phabricator. Bug reports are handled in Wikimedia Phabricator.
This static website is read-only and for historical purposes. It is not possible to log in and except for displaying bug reports and their history, links might be broken. See T62810, the corresponding Phabricator task for complete and up-to-date bug report information.

Certain thumbnails fail to generate/load through thumb.php
Examples:

https://commons.wikimedia.org/w/thumb.php?w=300&f=Vicinity_of_Pigeon_Point_Lighthouse.jpg&action=purge
https://commons.wikimedia.org/w/thumb.php?w=300&f=Pigeon_portrait_4861.jpg

Error 304 (Not Modified) is returned for those. Appending action=purge does not help. However the example above work when a width of 299 or 301 px is selected.

https://commons.wikimedia.org/w/index.php?title=File:Pigeon_portrait_4861.jpg&action=purge and https://commons.wikimedia.org/wiki/File:Vicinity_of_Pigeon_Point_Lighthouse.jpg?action=purge fixed those

Closing as per last comment.