Comment 20 for bug 1505014

(In reply to Stéphane Tréboux from comment #14)
> I just updated to KDE Applications 15.12. In the Dolphin preferences under
> General -> Previews the following options are available and ticked:
> - PS/PDF/DVI (provided by kdegraphics-thumbnailers 15.12.3)
> - video files (provided by ffmpegthumbs 15.12.3)
> Still no thumbnails are generated. Any idea what could be missing?

Distribution ?
If Ubuntu then it is a packaging bug: https://www.kubuntuforums.net/showthread.php?69996-No-video-amp-pdf-files-preview-in-Dolphin-15-12-3&p=386740&viewfull=1#post386740
Bug should be filed to the Launchpad: https://launchpad.net/ubuntu/+source/ffmpegthumbs/+bugs