The same thing happens for me when I run firefox on a vnc-server and display it in a vnc client. Worked fine in previous package version. Running Ubuntu 16.10 and this started after restarting firefox after apt-get update; apt-get upgrade.
firefox package version 50.0+build2-0ubuntu0.16.10.2
The same thing happens for me when I run firefox on a vnc-server and display it in a vnc client. Worked fine in previous package version. Running Ubuntu 16.10 and this started after restarting firefox after apt-get update; apt-get upgrade.
firefox package version 50.0+build2- 0ubuntu0. 16.10.2