media library thumbnails missing for txt and pdf The http://drupal.org/project/media module cannot display the thumbnails of txt and pdf files in my installation. I'm not expecting a thumbnail of the actual txt or pdf content of course but a generic placeholder.

Display as list:


Display as thumbnail:


Note that:


no missing file (404) requests are being tracked in firebug
this also affects the media popup file chooser from within content editing
changing the theme doesn't solve this problem
inspecting the "empty thumbnail" with firebug doesn't show anything useful, the &lt;a /&gt; is empty.
Using 7.x-2.x-dev instead of 7.x-1.1 solves this.