Unable to Map Picture to AD thumbnailPhoto in SharePoint 2013 User Profile

I'm not able to Map Picture to AD thumbnailPhoto in SharePoint 2013 User Profile:

• My current user have a Farm Permissions
• I'm able to edit picture in Manage User Properties
• When I choose thumbnailPhoto from drop down list and click OK, it returns back to Manage User Properties without mapping

Thanks in advance

Finally, it is working, it was a very stupid actually, I was not clicking on ADD button before OK !!! , stupid isn't :) ?