If you click the "X" button to close the Properties window, it will not render properly the next time you open it. Using the "Close" button instead does not trigger the faulty behavior. Terminal output: wrapper-2.0:7138): Gtk-CRITICAL **: gtk_container_foreach: assertion 'GTK_IS_CONTAINER (container)' failed Version: xfce4-indicator-plugin 2.3.1-0ubuntu1 Distribution: Xubuntu 14.04 LTS (Dev)
Should be now fixed in: 162fac0 Fix blank properties window, but #10749
I applied your patch and can confirm that it resolves the problem. Thanks!
FIXED