Oh, it seems Firefox/GTK needs fixing. It's trying to use both X11 (bug 1668429) and native Mir:
Feb 27 14:31:01 kg-Studio-1737 firefox[6135]: /build/gtk+3.0-MH7ynA/gtk+3.0-3.22.7/./gdk/x11/gdkwindow-x11.c:5573 drawable is not a native X11 window Feb 27 14:31:01 kg-Studio-1737 firefox[6135]: Ignoring unknown Mir event 11 Feb 27 14:31:01 kg-Studio-1737 firefox[6135]: Ignoring unknown Mir event 8 ** Changed in: firefox (Ubuntu) Status: Invalid => Confirmed ** Package changed: libertine (Ubuntu) => gtk+3.0 (Ubuntu) ** Changed in: unity8 (Ubuntu) Status: Confirmed => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1668409 Title: Firefox fails to launch in unity8 zesty To manage notifications about this bug go to: https://bugs.launchpad.net/canonical-devices-system-image/+bug/1668409/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs