Please advise how to disable automatic updates on Firefox running on Linux Kubuntu. Solutions posted on mozilla.org do not work because stated disable options are not available(see screenshot). I have set app.auto.update to false in about:config but this does not disable updates. I have been repeatedly advised not to disable updates so I am aware of the so called risk. I am very tired of every update breaking a reliable browser and having to repair/fix/workaround each and every time. Please provide a viable solution.