I'm on Ubuntu 21.10. I use gnome-flashback with Compiz. gnome-panel (version: 3.41.2) keeps crashing for me for some reason. Here's a log file but I can't seem to find what the problem is.
Gtk-Message: 14:07:17.772: Failed to load module "xapp-gtk3-module"
(gnome-panel:202571): indicator-applet-WARNING **: 14:07:17.936: Binding '<Super>F1' failed!
(gnome-panel:202571): indicator-applet-WARNING **: 14:07:17.937: Binding '<Super>F1' failed!
(gnome-panel:202571): indicator-applet-WARNING **: 14:07:17.938: Binding '<Super>F1' failed!
(gnome-panel:202571): indicator-applet-WARNING **: 14:07:17.964: Binding '<Super>S' failed!
(gnome-panel:202571): Indicator-Appmenu-CRITICAL **: 14:07:18.369: Unable to register the object to DBus: An object is already exported for the interface com.canonical.AppMenu.Registrar at /com/canonical/AppMenu/Registrar
(gnome-panel:202571): Indicator-Appmenu-CRITICAL **: 14:07:18.369: Unable to register the object to DBus: An object is already exported for the interface com.canonical.AppMenu.Registrar at /com/canonical/AppMenu/Registrar
(gnome-panel:202571): Indicator-Appmenu-CRITICAL **: 14:07:18.464: Unable to claim the name com.canonical.AppMenu.Registrar
(gnome-panel:202571): Indicator-Appmenu-CRITICAL **: 14:07:18.464: Unable to claim the name com.canonical.AppMenu.Registrar
(gnome-panel:202571): GLib-GObject-WARNING **: 14:07:24.041: invalid unclassed pointer in cast to 'GtkWidget'
(gnome-panel:202571): Gtk-CRITICAL **: 14:07:24.041: gtk_widget_set_sensitive: assertion 'GTK_IS_WIDGET (widget)' failed
...
(gnome-panel:202571): Gtk-CRITICAL **: 14:07:26.503: gtk_window_set_attached_to: assertion 'GTK_IS_WINDOW (window)' failed
(gnome-panel:202571): GLib-GObject-WARNING **: 14:07:26.503: invalid (NULL) pointer instance
(gnome-panel:202571): GLib-GObject-CRITICAL **: 14:07:26.504: g_signal_connect_data: assertion 'G_TYPE_CHECK_INSTANCE (instance)' failed
(gnome-panel:202571): Gtk-CRITICAL **: 14:07:26.504: gtk_window_set_screen: assertion 'GTK_IS_WINDOW (window)' failed
(gnome-panel:202571): GLib-GObject-WARNING **: 14:07:26.707: invalid unclassed pointer in cast to 'GtkWidget'
...
(gnome-panel:202571): GLib-GObject-WARNING **: 14:10:04.942: invalid unclassed pointer in cast to 'GtkWidget'
(gnome-panel:202571): Gtk-CRITICAL **: 14:10:04.942: gtk_widget_set_sensitive: assertion 'GTK_IS_WIDGET (widget)' failed
(gnome-panel:202571): Gtk-WARNING **: 14:11:06.528: ../../../../gtk/gtkwidget.c:6776: no accelerator (115,4) installed in accel group (0x55c819556660) for Genericmenuitem (0x55c819b549a0)
(gnome-panel:202571): Gtk-WARNING **: 14:11:06.528: ../../../../gtk/gtkwidget.c:6776: no accelerator (112,4) installed in accel group (0x55c819556660) for Genericmenuitem (0x55c819b54d80)
(gnome-panel:202571): Gtk-WARNING **: 14:11:06.528: ../../../../gtk/gtkwidget.c:6776: no accelerator (120,4) installed in accel group (0x55c819556660) for Genericmenuitem (0x55c819b5a1d0)
(gnome-panel:202571): Gtk-WARNING **: 14:11:06.528: ../../../../gtk/gtkwidget.c:6776: no accelerator (99,4) installed in accel group (0x55c819556660) for Genericmenuitem (0x55c819b5a5b0)
(gnome-panel:202571): Gtk-WARNING **: 14:11:06.528: ../../../../gtk/gtkwidget.c:6776: no accelerator (118,4) installed in accel group (0x55c819556660) for Genericmenuitem (0x55c819b5a990)
(gnome-panel:202571): Gtk-WARNING **: 14:11:06.528: ../../../../gtk/gtkwidget.c:6776: no accelerator (102,4) installed in accel group (0x55c819556660) for Genericmenuitem (0x55c819b5ad70)
(gnome-panel:202571): Gtk-WARNING **: 14:11:06.529: ../../../../gtk/gtkwidget.c:6776: no accelerator (104,4) installed in accel group (0x55c819556660) for Genericmenuitem (0x55c819b815b0)
(gnome-panel:202571): Gtk-WARNING **: 14:11:06.529: ../../../../gtk/gtkwidget.c:6776: no accelerator (117,4) installed in accel group (0x55c819556660) for Genericmenuitem (0x55c819b88d80)
(gnome-panel:202571): GLib-GObject-WARNING **: 14:11:06.613: invalid unclassed pointer in cast to 'GtkWidget'
...
(gnome-panel:202571): GLib-GObject-WARNING **: 14:11:07.160: invalid unclassed pointer in cast to 'GtkWidget'
(gnome-panel:202571): Gtk-CRITICAL **: 14:11:07.160: gtk_widget_set_sensitive: assertion 'GTK_IS_WIDGET (widget)' failed
(gnome-panel:202571): Indicator-Appmenu-CRITICAL **: 14:11:07.232: menus_destroyed: assertion 'IS_WINDOW_MENU(wm)' failed
(gnome-panel:202571): Indicator-Appmenu-CRITICAL **: 14:11:07.232: menus_destroyed: assertion 'IS_WINDOW_MENU(wm)' failed
(gnome-panel:202571): Indicator-Appmenu-CRITICAL **: 14:11:07.232: menus_destroyed: assertion 'IS_WINDOW_MENU(wm)' failed
(gnome-panel:202571): GLib-GObject-WARNING **: 14:11:08.079: invalid unclassed pointer in cast to 'GtkWidget'
(gnome-panel:202571): Gtk-CRITICAL **: 14:11:08.079: gtk_widget_set_sensitive: assertion 'GTK_IS_WIDGET (widget)' failed
...
(gnome-panel:202571): Gtk-CRITICAL **: 14:14:37.169: gtk_widget_set_sensitive: assertion 'GTK_IS_WIDGET (widget)' failed
(gnome-panel:202571): GLib-GObject-WARNING **: 14:14:37.228: invalid unclassed pointer in cast to 'GtkWidget'
(gnome-panel:202571): Gtk-CRITICAL **: 14:14:37.228: gtk_widget_set_sensitive: assertion 'GTK_IS_WIDGET (widget)' failed
Let's try to fix each warning or error step by step.
The below message
is fixable by installing the corresponding packages by:
Then message
should be fixed by installing the corresponding packages by
Then reboot and login to GNOME FlashBack (Compiz) session again.
Some IMHO is below.
Really GNOME FlashBack (with either Metacity or Compiz) will not solve usability loss of GNOME Shell in long-time perspective. So you are welcome to remove it and install normally fully traditional stable desktop named MATE which is a fork of GNOME 2. See the full list of reasons in this answer.
Installation of MATE is as simple as
sudo apt-get install ubuntu-mate-desktop^.Seems the answer is to move from old gnome-panel (Gnome2) to something more supported like Mate and mate-panel.