title: Attachment.PropertyAccessor.GetProperty for PR_ATTACH_DATA_BIN returns byte array with all items 0
body: <p>I have an Outlook add-in created for sending large file attachments.  When a user tries to attach a file it actually attaches a placeholder ".txt" file whose contents are the path to the actual attachment.  When the user sends the email the add-in tries to read the contents of the placeholder attachment in order to get the path to the actual attachment.  It does this using the <code>Attachment.PropertyAccessor.GetProperty</code> method while passing in the value <code>"http://schemas.microsoft.com/mapi/proptag/0x37010102"</code> (PR_ATTACH_DATA_BIN).  </p>
  
  <pre><code>byte[] attachmentData = attachment.PropertyAccessor.GetProperty(
    "http://schemas.microsoft.com/mapi/proptag/0x37010102");
  </code></pre>
  
  <p>This has been working for several years and I haven't updated my add-in for 4 months but it has been acting differently starting today.  Now the return value for this method returns a byte array of the correct length (in my case 93 for the 93-byte placeholder file) but all of the items in the byte array are 0.  If I open the placeholder file all of the contents look correct so I don't understand the issue.  We are currently on the latest build of Outlook 2016 (Version 1711 Build 8730.2127) and I've even tried reverting to the last 2 builds but the problem still occurs.</p>
  
  <p>Does anyone know if something has changed with Outlook 2016 regarding the MAPI?</p>
  
  <p>Note - I've tried using OutlookSpy to find out what's going on but the <code>GetAttachmentTable</code> tab shows no entries even though from the Outlook UI I can clearly see that there is an attachment.</p>