Hello Yenthe,
(thanks to the grand 5 karma limitation I am not able to upvote your question nor to comment it, but I think it is very helpful, therefore: thanks! If you would help me to earn one more karma point?)
I have tried uninstalling wkhtmltopdf by using
dpkg -r wkhtmltox,
then installed .12.1 , restarted the server. Didn't work. Installed .12.2, restarted the server. Didn't work. Installed .12.0, restarted the server. Didn't work. I have set and removed the System Variable under Settings --> Technical Settings --> Parameters --> System Parameters ... didn't work. Could you please tell me the exact process on how to remove everything wkhtml-ish and then reinstalling the old version?
*UPDATE*
It finally did work for me by setting the System Parameter to /usr/local/bin instead of /usr/bin . Both executables are the same, but - it works.
*UPDATE 2*
It did work exactly once. Thereafter, no footer. Dunno what to do next.