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 MonoDevelop.Projects.SolutionFolderItemCollection.OnItemAdded(SolutionItem item) at MonoDevelop.Projects.ItemCollection`1.InsertItem(Int32 index, T item) at System.Collections.ObjectModel.Collection`1.Add(T item) at MonoDevelop.Projects.SolutionFolder.AddItem(SolutionItem item, Boolean createSolutionConfigurations) at MonoDevelop.Ide.Projects.NewProjectDialog.OpenEvent(Object sender, EventArgs e) --- End of inner exception stack trace --- at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor) at System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object[] parameters, Object[] arguments) at System.Delegate.DynamicInvokeImpl(Object[] args) at GLib.Signal.ClosureInvokedCB(Object o, ClosureInvokedArgs args) at GLib.SignalClosure.Invoke(ClosureInvokedArgs args) at GLib.SignalClosure.MarshalCallback(IntPtr raw_closure, IntPtr return_val, UInt32 n_param_vals, IntPtr param_values, IntPtr invocation_hint, IntPtr marshal_data)