Hi Stefan

Thanks so much for this information. I don't think the policy option will be possible in my scenario.

Perhaps I need to automatically set all of the hidden fields to be no longer hidden rather than changing the setting. I assume this would be possible via C# extension?

Yes. Using the OpenXML SDK it is possible to access the fields. You would need to iterate over all paragraphs then all runs within a paragraph and then all elements within a run to get to the fields. (<- as far as my memory is right here). Although i have lots of openxml code i dont have a concrete example to share with you - never had the requirement to deal with fields within a word document :-(

Thanks Stefan.
I found the same through some research and came up with the following code which does the trick. Hope this can help someone else too.

using System;

using System.IO;

using DocumentFormat.OpenXml;

using DocumentFormat.OpenXml.Packaging;

using DocumentFormat.OpenXml.Wordprocessing;

class Program

{

    public static void MssUnhideAllFields(byte[] ssBinary_in, out byte[] ssBinary_out)

    {

        using (MemoryStream memoryStream = new MemoryStream(ssBinary_in))

        {

            using (WordprocessingDocument doc = WordprocessingDocument.Open(memoryStream, true))

            {

                var mainPart = doc.MainDocumentPart;

                var docBody = mainPart.Document.Body;

                foreach (var run in docBody.Descendants())

                {

                    var runProperties = run.RunProperties;

                    if (runProperties == null)

                        continue;

                    var vanishElement = runProperties.Vanish;

                    if (vanishElement != null)

                    {

                        // Remove the vanish element

                        runProperties.RemoveChild(vanishElement);

                    }

                }

                // Save the changes

                mainPart.Document.Save();

            }

            // Get the modified document's content as a byte array

            ssBinary_out = memoryStream.ToArray();

        }

    }

    public static void Main(string[] args)

    {

        byte[] inputBinary = /* your binary data here */ ; // Replace with your binary document data

        byte[] outputBinary;

        MssUnhideAllFields(inputBinary, out outputBinary);

        // Now you can use the outputBinary for further processing or output

    }

}