Exchange 2010 - nelze přidat pravidlo pro transport

Pokaždé, když v Exchangi kliknu na New Transport Rule, tak se mi zobrazí tato chyba:

 v System.RuntimeMethodHandle._InvokeMethodFast(Object target, Object[] arguments, SignatureStruct& sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner)
   v System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks)
   v System.Delegate.DynamicInvokeImpl(Object[] args)
   v Microsoft.Exchange.Management.SystemManager.ExpressionCalculator.CalculateLambdaExpression(ColumnExpression expression, Type dataType, DataRow dataRow, DataRow inputRow)
   v Microsoft.Exchange.Management.SystemManager.ExpressionCalculator.CalculateCore(DataRow dataRow, DataRow inputRow, IList`1 query)
   v Microsoft.Exchange.Management.SystemManager.WinForms.AutomatedDataHandlerBase.FillColumnsBasedOnOnceLambdaExpression()
   v Microsoft.Exchange.Management.SystemManager.WinForms.AutomatedDataHandlerBase.UpdateTable(DataRow row, String targetConfigObject, Boolean isOnReading)
   v Microsoft.Exchange.Management.SystemManager.WinForms.AutomatedDataHandler.OnReadData(CommandInteractionHandler interactionHandler, String pageName)
   v Microsoft.Exchange.Management.SystemManager.WinForms.DataHandler.Read(CommandInteractionHandler interactionHandler, String pageName)
   v Microsoft.Exchange.Management.SystemManager.WinForms.DataContext.ReadData(CommandInteractionHandler interactionHandler, String pageName)
   v Microsoft.Exchange.Management.SystemManager.WinForms.ExchangePage.<OnSetActive>b__0(Object sender, DoWorkEventArgs e)
   v System.ComponentModel.BackgroundWorker.WorkerThreadStart(Object argument)

Neočekávaná koncová značka Řádek 1, pozice 57
   v System.Xml.XmlTextReaderImpl.Throw(Exception e)
   v System.Xml.XmlTextReaderImpl.ParseDocumentContent()
   v System.Xml.XmlLoader.ParsePartialContent(XmlNode parentNode, String innerxmltext, XmlNodeType nt)
   v System.Xml.XmlLoader.LoadInnerXmlElement(XmlElement node, String innerxmltext)
   v Microsoft.Exchange.Management.SystemManager.MarkupParser.set_Markup(String value)
   v Microsoft.Exchange.Management.SnapIn.Esm.RuleEditor.RuleEditorCommon.GenerateExceptionsDescriptor(IList predicates, IList actions)
   v lambda_method(ExecutionScope , String , String )

Čím by mohla být způsobena?