Prüfung beim MailItem mittels TryCast, ob Mailobjekt nicht beschädigt ist.

VERAGAddIn/rbnVERAG.vb

@@ -106,12 +106,21 @@ Public Class AVISO_Mail_Functions
             Dim explorer As Outlook.Explorer = Globals.ThisAddIn.Application.ActiveExplorer
             Dim selection As Outlook.Selection = explorer.Selection
             If selection.Count > 0 Then
-                Dim selectedItem = selection(1)
-                Dim mailItem As Outlook.MailItem = selectedItem
-                mailItem = DirectCast(mailItem, Outlook.MailItem)
+                Dim selectedItem As Object = selection(1)
 
-                addMailToAviso(mailItem, isFormular)
+                Dim result = TryCast(selectedItem, Outlook.MailItem)
+
+                If result IsNot Nothing Then
+
+                    Dim mailItem As Outlook.MailItem = selectedItem
+                    mailItem = DirectCast(mailItem, Outlook.MailItem)
+
+                    addMailToAviso(mailItem, isFormular)
+                Else
+                    MsgBox("Die markierte Email kann nicht verarbeitet werden!" & vbNewLine & "Bitte andere Mail verwenden.")
+                End If
             End If
+
         Catch ex As Exception
             MsgBox(ex.Message & ex.StackTrace)
         End Try