Ambiguity between 'Microsoft.Office.Interop.Word._Application.NewDocument' and 'M
I am trying to add a NewDocument event handler to my VSTO 2005 SE add-in for Word 2007. I get an error message on the following line. Is this a VSTO bug?
this.Application.NewDocument +=new Microsoft.Office.Interop.Word.ApplicationEvents4_NewDocumentEventHandler(Application_NewDocument);
Ambiguity between 'Microsoft.Office.Interop.Word._Application.NewDocument' and 'Microsoft.Office.Interop.Word.ApplicationEvents4_Event.NewDocument'
Depends on what you call a bug 
If it's intended behaviour it isn't. The thing is that in your case there is a collision between the NewDocument method and the NewDocument event on the Application object.
This is causing the message you get. Easiest way in my opinion I think would be to cast the this.Application.NewDocument part to the event used here.
-= Maarten =-
Thanks for your reply, Maarten. I suspect it's not intended behavior and could be considered a bug.
It certainly messes up IntelliSense and Visual Studio can't automatically generate the NewDocument event handler for you.
But you're right about the cast. It worked when I changed it to:
((Word.
ApplicationEvents4_Event)this
.Application).NewDocument +=new
Microsoft.Office.Interop.Word.ApplicationEvents4_NewDocumentEventHandler(ThisAddIn_NewDocument); 
