Preview run for Method #1 didn't load completely

I completed the entire process for Method #1 in creating a Presell Page.
I checked the link was correct in the edit.
I did the test preview. The page ran through the first section then went to a page that
said “Can’t load page”. OMG so frustrated. Not sure how to determine why it didn’t load the entire page. So now I don’t have an ad running.