This article applies to the 123-reg InstantSite package.
This article will explain how you can fix a InstantSite blank page issue with the click of a button.
Please follow the below steps in order to resolve this issue.
Scroll down to the Create your website section and click on the InstantSite icon.
Click on the Login button next to the relevant InstantSite package.
Click on the Edit link.
Please ensure that the check box for Show this page in site map is ticked.
Click on the Save Changes button.
Click on the Publish button.