Unsettings crashes when closing without saving changes, then selecting "Yes"

Behaviour: modify something like: disable the global menu or overlay scrollbars -> try to quit application (without saving the changes) -> the application prompts you to save changes, select "Yes" -> application crashes. Here's the error:

/usr/lib/python2.7/dist-packages/gobject/constants.py:24: Warning: g_boxed_type_register_static: assertion `g_type_from_name (name) == 0' failed
  import gobject._gobject

Gtk-WARNING **: Unknown property: GtkMenuBar.ubuntu-local

Gtk-WARNING **: Unknown property: GtkMenu.ubuntu-local

Gtk-WARNING **: Unknown property: GtkMenu.ubuntu-local

Gtk-WARNING **: Unknown property: GtkMenu.ubuntu-local

Gtk-WARNING **: Unknown property: GtkMenu.ubuntu-local
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/unsettings/main.py", line 195, in on_window1_delete_event
    self.quit()
  File "/usr/lib/python2.7/dist-packages/unsettings/main.py", line 180, in quit
    apply_settings()
NameError: global name 'apply_settings' is not defined

Also, the changed setting durring the above mentioned behaviour are not saved.