Hi
I have done below changes, but it didn't resolved the issue
Line 846 of osticket/js/jquery.pjax.js
timeout: 3000,
I have installed 1.11 Latest Release.
Server Details are as below
Apache Version 2.2.31
PHP Version 5.6.35
MySQL Version 5.6.41-84.1
Operating System linux
Let me know if any additional information require in this regard from my end.