System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.NotImplementedException: The requested feature is not implemented.
  at MonoDevelop.Ide.TypeSystem.CodeGenerationService.GetSuitableInsertionPoint (IEnumerable`1 points, IUnresolvedTypeDefinition cls, IUnresolvedMember member) [0x0003e] in /build/buildd/monodevelop-3.0.1/main/src/core/MonoDevelop.Ide/MonoDevelop.Ide.TypeSystem/CodeGenerationService.cs:335
  at MonoDevelop.Ide.TypeSystem.CodeGenerationService.AddNewMember (ITypeDefinition type, IUnresolvedTypeDefinition part, IUnresolvedMember newMember, Boolean implementExplicit) [0x00043] in /build/buildd/monodevelop-3.0.1/main/src/core/MonoDevelop.Ide/MonoDevelop.Ide.TypeSystem/CodeGenerationService.cs:91
  at MonoDevelop.GtkCore.GuiBuilder.CodeBinder.BindSignal (Stetic.Signal signal) [0x000de] in /build/buildd/monodevelop-3.0.1/main/src/addins/MonoDevelop.GtkCore/MonoDevelop.GtkCore.GuiBuilder/CodeBinder.cs:182
  at MonoDevelop.GtkCore.GuiBuilder.GuiBuilderView.OnSignalAdded (System.Object sender, Stetic.ComponentSignalEventArgs args) [0x00000] in /build/buildd/monodevelop-3.0.1/main/src/addins/MonoDevelop.GtkCore/MonoDevelop.GtkCore.GuiBuilder/GuiBuilderView.cs:316
  at Stetic.WidgetDesigner.OnSignalAdded (System.Object sender, Stetic.ComponentSignalEventArgs args) [0x00000] in <filename unknown>:0
  at Stetic.Project+<NotifySignalAdded>c__AnonStoreyD.<>m__17 (System.Object , System.EventArgs ) [0x00000] in <filename unknown>:0
  at Stetic.GuiDispatch.InvokeSync (System.EventHandler h) [0x00000] in <filename unknown>:0
  at Stetic.Project.NotifySignalAdded (System.Object obj, System.String name, Stetic.Signal signal) [0x00000] in <filename unknown>:0
  at (wrapper remoting-invoke-with-check) Stetic.Project:NotifySignalAdded (object,string,Stetic.Signal)
  at Stetic.ProjectBackend.Stetic.IProject.NotifySignalAdded (Stetic.SignalEventArgs args) [0x00000] in <filename unknown>:0
  at Stetic.ObjectWrapper.OnSignalAdded (Stetic.SignalEventArgs args) [0x00000] in <filename unknown>:0
  at Stetic.SignalCollection.OnInsertComplete (Int32 index, System.Object value) [0x00000] in <filename unknown>:0
  at System.Collections.CollectionBase.System.Collections.IList.Add (System.Object value) [0x00000] in <filename unknown>:0
  --- End of inner exception stack trace ---
  at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0
  at System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) [0x00000] in <filename unknown>:0
  at System.Delegate.DynamicInvokeImpl (System.Object[] args) [0x00000] in <filename unknown>:0
  at System.MulticastDelegate.DynamicInvokeImpl (System.Object[] args) [0x00000] in <filename unknown>:0
  at System.Delegate.DynamicInvoke (System.Object[] args) [0x00000] in <filename unknown>:0
  at GLib.Signal.ClosureInvokedCB (System.Object o, GLib.ClosureInvokedArgs args) [0x00000] in <filename unknown>:0
  at GLib.SignalClosure.Invoke (GLib.ClosureInvokedArgs args) [0x00000] in <filename unknown>:0
  at GLib.SignalClosure.MarshalCallback (IntPtr raw_closure, IntPtr return_val, UInt32 n_param_vals, IntPtr param_values, IntPtr invocation_hint, IntPtr marshal_data) [0x00000] in <filename unknown>:0