Thanks Srivatsava for the reply.
I have unchecked the check box on C4C as you have done and now I can see a pop up coming up but without any PDF content.
But for the changes that you did for mapping, I couldn't see the message mapping as you have shown in the screen shot. It looks as shown in screen shot below. Could you please elaborate more on the custom mapping as we have never worked on any custom mapping scenario.
Regards,
Chandan