How to receive transferred files inn UCMA IM conversation ?

I want my UCMA application to accept\receive files sent over IM conversation and save it on disk

Current tried out implementation

• byte[] fileBytes = InstantMessageReceivedEventArgs.MessageData.GetMessageBody();
• File.WriteAllBytes("C:\\image.JPG", fileBytes);

The file gets saved on disk but i cannot preview it .

Another problem is accept file invitation at lync client is does not changes to "Accepted" hence the user is not acknowledge about transfer accepted or  transfer complete and gets  "error in transfer" after some time.

Note :I'm using ApplicationEndpoint for UCMA application.

Do i need to add some additional media capabilities(file types allowed) to Instant Message call .If yes, how to achieve this in UCMA ?