These days, Firefox is updated on a quite frequent basis; however, normally, I don’t see any obvious changes resulting in any of the new versions. This was not the case recently when, inexplicably, PDF file started being opened inside Firefox’s window rather than externally to the browser. I have to say that I don’t like this new behaviour, but how do I change it back?
Most of the hits from a Google search on the issue were for users wanting the exact opposite. PDF files were being opened in a viewer and they wanted them to be displayed within the browser. But, these postings did remind me of the name of Ubuntu’s default PDF reader – Evince.
With this information at hand, the solution to my problem was simple. In Firefox, navigate to Edit – Preferences – Applications – PDF document – Use other. In the file selection dialogue box, browse to /usr/bin/evince and press the Open button. Select the “Use evince” option and press Close.
PDF files now open in the Evince document viewer. Job done.