the error is produced by the extension of ubuntu one
Console message:
Exception in Gtk# callback delegate
Note: Applications can use GLib.ExceptionManager.UnhandledException to handle the exception.
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 Banshee.UbuntuOneMusicStore.UbuntuOneMusicStoreSource.OnDefaultStoreUrlLoaded (System.Object o, UbuntuOne.UrlLoadedArgs args) [0x00000] in <filename unknown>:0
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 <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
at GLib.ExceptionManager.RaiseUnhandledException(System.Exception e, Boolean is_terminal)
at GLib.SignalClosure.MarshalCallback(IntPtr raw_closure, IntPtr return_val, UInt32 n_param_vals, IntPtr param_values, IntPtr invocation_hint, IntPtr marshal_data)
at Gtk.Application.gtk_main()
at Gtk.Application.Run()
at Banshee.Gui.GtkBaseClient.Run()
at Banshee.Gui.GtkBaseClient.Startup()
at Hyena.Gui.CleanRoomStartup.Startup(Hyena.Gui.StartupInvocationHandler startup)
at Banshee.Gui.GtkBaseClient.Startup()
at Banshee.Gui.GtkBaseClient.Startup(System.String[] args)
at Nereid.Client.Main(System.String[] args)
at System.AppDomain.ExecuteAssembly(System.AppDomain , System.Reflection.Assembly , System.String[] )
at System.AppDomain.ExecuteAssemblyInternal(System.Reflection.Assembly a, System.String[] args)
at System.AppDomain.ExecuteAssembly(System.String assemblyFile, System.Security.Policy.Evidence assemblySecurity, System.String[] args)
at System.AppDomain.ExecuteAssembly(System.String assemblyFile)
at Booter.Booter.BootClient(System.String clientName)
at Booter.Booter.Main()
Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 871068, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Feel free to continue to report any other bugs you may find.