Most likely not related to the actual problem, but you could try to fix the Gtk message first (bug 1134202).
The next step is to install a more recent version of xfwm4 and test again. You can use one of the following PPAs or compile it from source: https://launchpad.net/~thad-fisch/+archive/ubuntu/xfce-git https://launchpad.net/~xubuntu-dev/+archive/ubuntu/xfce-4.12 Furthermore, I suggest that you forward this bug upstream. Thanks in advance. https://bugzilla.xfce.org/ -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1400679 Title: Firefox and Thunderbird icons missing when alt-tabbing To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xfwm4/+bug/1400679/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
