This script will scan all publishing pages in a given site collection and check if the pages in the pages library have a valid url for the page layout. The script runs in a “detect” mode by default and also accepts parameters which allow fixing the page layout url for pages. If the page is checked out to someone else, you can force undo of the checkout (results in changes on that page being lost). When fixing the page layout url, it will also checkout and approve the pages post fixing if moderation is enabled. It does not publish the pages.
Having a correct page layout is important when rendering pages in publishing site or when using features such as Variations or Content Deployment because these will fail if the referenced page layout is invalid or pointing to a location which is not valid in the context of the site.
In a real world, this script will help fix issues wherein
a. Variations create hierarchies fail because the page layout is invalid.
b. Page rendering fails because the page layout is invalid.
You can find more All-In-One Script Framework script samples at https://aka.ms/onescriptingallery