Some elements in Microsoft Word could be missing during initial setup. Try the following steps in order to resolve.
  1. Access the existing letter templates in Word that appear after clicking Create or Edit merge document.
  2. Go to the Developer tab
  3. Click Add-Ins
  4. Go to the XML Schema tab
  5. Mark the option: ActionsPane Schema for Add-ins
  6. Click OK
  7. Uninstall/reinstall Microsoft Office

If you need assistance with this, contact your IT department or qualified computer personnel. Installation of Microsoft Word is beyond our Scope of Support.