Testing my VB.NET 2010 app in ArcMap an exception occurs when ICommandBars is instantiated. ' zoom to selected Dim mxApp As ESRI.ArcGIS.Framework.IApplication Dim numUID As UID = New ESRI.ArcGIS.esriSystem.UID numUID.Value = "{AB073B49-DE5E-11D1-AA80-00C04FA37860}" Dim commandBars As ICommandBars = mxApp.Document.CommandBars '>>> error here!!!!!!!! Dim cmdItem As ICommandItem = CommandBars.Find(numUID, False, False) If Not (cmdItem Is Nothing) Then cmdItem.Execute() End IfMessage: Exception first-chance type 'System.NullReferenceException' in LUCAS.dll.Please can anybody help me?Thanks in advance.ALP.S. ArcGIS 10 SP1 on Windows 7, VS2010.