still with Macintosh OS X.7 - Lion. Pinta1.3 running in MonoDevelop there is no error from "Gaussian Blur" - but no image results either. the Effect "Edge Detect" produces this error - System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.NullReferenceException: Object reference not set to an instance of an object at Pinta.Gui.Widgets.AnglePickerWidget..ctor () [0x0000c] in /Users/awol/Downloads/pinta-1.3/Pinta.Gui.Widgets/Widgets/AnglePickerWidget.cs:22 at Pinta.Gui.Widgets.SimpleEffectDialog.CreateAnglePicker (System.String caption, System.Object o, System.Reflection.MemberInfo member, System.Object[] attributes) [0x0001b] in /Users/awol/Downloads/pinta-1.3/Pinta.Gui.Widgets/Dialogs/SimpleEffectDialog.cs:308 at Pinta.Gui.Widgets.SimpleEffectDialog.BuildDialog () [0x001bf] in /Users/awol/Downloads/pinta-1.3/Pinta.Gui.Widgets/Dialogs/SimpleEffectDialog.cs:109 at Pinta.Gui.Widgets.SimpleEffectDialog..ctor (System.String title, Gdk.Pixbuf icon, System.Object effectData) [0x00092] in /Users/awol/Downloads/pinta-1.3/Pinta.Gui.Widgets/Dialogs/SimpleEffectDialog.cs:61 at Pinta.EffectHelper.LaunchSimpleEffectDialog (Pinta.Core.BaseEffect effect) [0x0003e] in /Users/awol/Downloads/pinta-1.3/Pinta.Effects/Utilities/EffectHelper.cs:45 at Pinta.Effects.EdgeDetectEffect.LaunchConfiguration () [0x00000] in /Users/awol/Downloads/pinta-1.3/Pinta.Effects/Effects/EdgeDetectEffect.cs:48 at Pinta.Core.LivePreviewManager.Start (Pinta.Core.BaseEffect effect) [0x001e3] in /Users/awol/Downloads/pinta-1.3/Pinta.Core/Managers/LivePreviewManager.cs:123 at Pinta.Core.EffectsManager+c__AnonStorey8.<>m__A (System.Object sender, System.EventArgs e) [0x00000] in /Users/awol/Downloads/pinta-1.3/Pinta.Core/Managers/EffectsManager.cs:99 at (wrapper managed-to-native) System.Reflection.MonoMethod:InternalInvoke (System.Reflection.MonoMethod,object,object[],System.Exception&) at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in :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 :0 at System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) [0x00000] in :0 at System.Delegate.DynamicInvokeImpl (System.Object[] args) [0x00000] in :0 at System.MulticastDelegate.DynamicInvokeImpl (System.Object[] args) [0x00000] in :0 at System.Delegate.DynamicInvoke (System.Object[] args) [0x00000] in :0 at GLib.Signal.ClosureInvokedCB (System.Object o, GLib.ClosureInvokedArgs args) [0x00000] in :0 at GLib.SignalClosure.Invoke (GLib.ClosureInvokedArgs args) [0x00000] in :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 :0