Staging process completed but 404 link

I tried twice to create a staging site. Both times it went smoothly with no error. I get the Congratulations message. However, when I click on the button saying “Open Staging site” it leads to a 404 error page. It happened twice, with two different tries, using 2 different names for the staging site.

Here is the link to the second one: http://scrapbookcampus.com/test-campus/

Is there any setting issue? Or is it just because it is not compatible with WP 4.9.4?