A URL mapping is currently in place redirecting [Page URL] to [Redirected URL]. Consider changing the URL for this or deleting the existing URL mapping. Learn more.
This error appears when you try to publish a page that has a previously redirected URL.
To resolve this issue, you'll need to edit the settings for the existing URL mapping to not redirect if a page exists at that URL, or delete the URL mapping all together. Alternatively, you can edit the URL to publish to for your new page.