Accessing Word Shape.Type throws COMException (HRESULT: 0x80004005 E_FAIL)

Question

I'm working with a C# program that must parse the text boxes and other contents of Microsoft Word documents. To do this, I'm utilizing the Microsoft.Office.Interop.Word library. But when I try to filter the shapes by type, looking for text boxes in particular, I get a COMException.

The line of code that is causing the problem is as follows:

var textBoxContents = doc.Shapes.Cast<Word.Shape>()
                .Where(shape =>
                {
                    try
                    {
                        return shape.Type == Microsoft.Office.Core.MsoShapeType.msoTextBox;
                    }
                    catch (System.Runtime.InteropServices.COMException)
                    {
                        // Skip this shape if an exception occurs while accessing its Type property
                        return false;
                    }
                })
                .Select(shape => shape.TextFrame.TextRange)
                .ToList();

When the line shape.Type == Microsoft.Office.Core.MsoShapeType.msoTextBox is executed, and the following exception is thrown:

System.Runtime.InteropServices.COMException: 'Unspecified error (Exception from HRESULT: 0x80004005 (E_FAIL))'

To handle the error and avoid the problematic shapes, I added a try-catch block, but this didn't seem to resolve the problem.

Has anyone else had this issue, and if so, how can I access the Shape.Type property correctly without running into this exception? Is there a solution or a better way to use the Microsoft.Office.Interop.Word library to extract text boxes from a Word document?

I would be very grateful for any assistance.