(MonoDevelop:29620): Gtk-WARNING **: Attempting to add a widget with type __gtksharp_46_Stetic_Placeholder to a __gtksharp_93_Stetic_CustomWidget, but as a GtkBin subclass a __gtksharp_93_Stetic_CustomWidget can only contain one widget at a time; it already contains a widget of type __gtksharp_46_Stetic_Placeholder
(MonoDevelop:29620): Gtk-CRITICAL **: gtk_drag_begin: assertion `GTK_WIDGET_REALIZED (widget)' failed
System.NullReferenceException: Object reference not set to an instance of an object
at Stetic.Wrapper.Container.CreateDragSource (Gtk.Widget dragWidget) [0x00000]
at Stetic.Wrapper.Container.HandleWindowDrag (Gdk.EventMotion evt) [0x00000]
at (wrapper delegate-invoke) System.MulticastDelegate:invoke_void_EventMotion (Gdk.EventMotion)
at Stetic.ObjectSelection.FireDrag (Gdk.EventMotion evt) [0x00000]
at Stetic.SelectionHandlePart.OnMotionNotifyEvent (Gdk.EventMotion evm) [0x00000]
at Gtk.Widget.motionnotifyevent_cb (IntPtr widget, IntPtr evnt) [0x00000]
at (wrapper native-to-managed) Gtk.Widget:motionnotifyevent_cb (intptr,intptr)
at <0x00000> <unknown method>
at (wrapper managed-to-native) Gtk.Application:gtk_main ()
at Gtk.Application.Run () [0x00000]
at MonoDevelop.Ide.Gui.IdeApp.Run () [0x00000]
at MonoDevelop.Ide.Gui.IdeStartup.Run (System.String[] args) [0x00000]
at MonoDevelop.Core.AddIns.AddInService.StartApplication (System.String addinId, System.String[] parameters) [0x00000]