Getting "warning" -- "Late bound resolution, runtime errors could occur" with a line referencing a Word document

Question

The problem line is:
            Dim Author$ = wd.ActiveDocument.BuiltInDocumentProperties(WdBuiltInProperty.wdPropertyAuthor).value.ToString
"wd" is my program's instance of Microsoft Word.
I've encountered this error before and could always fix the program and get rid of the warning without having to enclose the line in a "Try..Catch" structure. I enclosed this line in a Try..Catch, but the warning still appears, and for some reason,
I have dedicated my few remaining years to getting rid of it.
Robert Homes

Answer 1

Armin:
That didn't work for me. I couldn't even compile it like that, and I changed it to:
=============================================
        Dim props As Microsoft.Office.Core.DocumentProperties = _
                DirectCast(wd.ActiveDocument.BuiltInDocumentProperties, _
Microsoft.Office.Core.DocumentProperties)
        Dim Author$ = props(WdBuiltInProperty.wdPropertyAuthor).Value.ToString
=============================================
That at least allowed me to compile (and DID get rid of the warning), but then I got a runtime error:
========================================================
An unhandled exception of type 'System.InvalidCastException' occurred in Share.exe
Additional information: Unable to cast COM object of type 'System.__ComObject' to interface type 'Microsoft.Office.Core.DocumentProperties'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{2DF8D04D-5BFA-101B-BDE5-00AA0044DE52}'
failed due to the following error: No such interface supported (Exception from HRESULT: 0x80004002 (E_NOINTERFACE)).
================================================================================
Robert Homes