Hi,
Just now I found one cause of the issue, but dont understand why it is.
Whenever that document is having some comments (Track Changes and Comments from other user), and if those comments are not yet accepted, Aspose removes bookmarks from that document.
But if you accept those comments from word document and save it and then try with Aspose, it works perfectly fine and does not removes bookmarks from it.
Please can you tell me what can be the reason of such behaviour.