Image Gallery Null Object Error

I have a page containing multiple image galleries and thumbnail scrollers pulling in from external XMLs. The first scene containing gallery 1 loads the thumb and full size image perfectly.

We I navigate to the second scene containing a new instance of my scrollpanel and container movie clip for my full size image I this error: Error #1009: Cannot access a property or method of a null object reference.
at index_fla::MainTimeline/index_fla::frame6()

I am wondering if I have to remove an event listener from the previous frame. Everything on the stage has an instance name and I am calling all new variable son the second frame.

Any suggestions or tips would be supremely appreciated. I’m tearing my hair out on this one as I’m sure I am missing something simple.