Window.parent.opener not working in CRM 2016

HI,

I have a script which worked fine until CRM 2016. After debugging I found it is failing on this line:

  if (Form_Type == 1 && window.parent.opener != null) {

I am wondering if there is a different approach in CRM 2016 to access parent form details. Can somebody please direct me through this?

Thanks for any help.