Some additional information:
(glade-3:20950): GLib-GObject-WARNING **: gsignal.c:2270: signal `delete' is
invalid for instance `0x21a46ee50'
(glade-3:20950): GladeUI-CRITICAL **: glade_command_create: assertion
`GLADE_IS_WIDGET_ADAPTOR (adaptor)' failed
(glade-3:20950): GladeUI-CRITICAL **: glade_widget_get_name: assertion
`GLADE_IS_WIDGET (widget)' failed
(glade-3:20950): GladeUI-CRITICAL **: glade_widget_property_set: assertion
`GLADE_IS_WIDGET (widget)' failed
(glade-3:20950): GladeUI-CRITICAL **: glade_widget_property_set: assertion
`GLADE_IS_WIDGET (widget)' failed
Steps to recreate:
$ glade-3
1) start with defaults
2) select toplevel window (signal delete warnings happens here)
3) select vertical box (accept defaults)
4) select menu bar and add to vertical box
5) right click on menu bar and select Edit...
6) click on hierarchy tab
7) select imagemenuitem1 or _File
8) click + Add button, nothing happens (remaining errors from above happen here)
