Good morning, I'm using Kubuntu 16.04 the problem I have and I have not been able to solve is that although the preview should be seen, I do not, I already installed the kdegraphics-thumbnailers and active this in dolphin, but it still does not work, thanks for the help that you can give me.
This seems to be an Ubuntu bug: kdegraphics-thumbnailers 4:15.12.3-0ubuntu1 uses the wrong path for plugin libraries: https://bugs.launchpad.net/ubuntu/+source/kdegraphics-thumbnailers/+bug/1574049
Yup, this is a packaging bug. Note that there is a workaround: sudo ln -s /usr/lib/x86_64-linux-gnu/plugins/* /usr/lib/x86_64-linux-gnu/qt5/plugins/ Also note that the issue seems to be fixed in later Ubuntu versions. I'm using Kubuntu 17.04 and the issue has since been fised there.