No pop up to downlaod PDF file In Web Dispatcher as backend EP

Hi Guys,

We gave set our webdispatcher 741 with the latest kernel. Now we are using the system EP as backend. When we are trying to down laod the pdf file from the system we are getting pop_up 'Front end Service methods need ITS frame set" after that it hangs their. Could you please help me to resolve this. attached snapshot is for your reference.

BR,

Satyabrat