I am Getting an error in generating pdf

Sep 16 2019 9:46 AM

hey in my project i am using itext sharp for pdf generation below is my code. it is giving me error of object reference is not set soplease help me. i am using wizard control and in the 6th step i am generating pdf which is in panel contrl so i want to generate pdf of panel control

https://drive.google.com/open?id=1XJZY3TSn5piC5zVNHxr0lpmh5lXan5Rw