How can i make it compatible with this code?

How can i make it compatible with this code?
I am now having issues when I previewed the post and I would like to get back to the edit form the WYSIWYG editor doesn’t load the saved post.
http://gravitywiz.com/better-pre-submission-confirmation/

Thank you in advance,
Chief 😀

http://ww.wp.xz.cn/extend/plugins/gravity-forms-wysiwyg/