Thanks for coming back..
User is using only IE plugin.. and server and plugin both are having same version : 11.20.12746. this issue is only for one of the user.
I have tried to add Accesspoint in Local Intranet, reset full IE setting and reinstall IE plugin twice but nothing is helping..
really I need to fix urgently.. I would really appreciate to get suggestion soon..
IE version 10 and Windows 7
Thanks in advance!!