Exception Lifeline (#297)
System.NullReferenceException: Object reference not set to an instance of an object.
at SoftwareIdeasModeler.Core.Commands.ContextCommands.ConvertToTimingValueLifelineCommand.Execute()
at SoftwareIdeasModeler.Core.Commands.ContextCommands.ConvertToTimingValueLifelineCommandPrototype.Execute()
at SoftwareIdeasModeler.Core.Projecting.CommandStack.AddCommand(Command command, Boolean execute)
at SoftwareIdeasModeler.Core.Projecting.Project.Execute(Command cmd)
at SoftwareIdeasModeler.ContextToolbar.MouseUp(MouseEventArgs e)
at SoftwareIdeasModeler.SimDiagramControl.canvas_MouseUp(Object sender, MouseEventArgs e)
at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)