Usually the wiki will prevent users from creating multiple pages with the same URL in a single namespace, but if the URL Replacement rules have changed, it's possible that some existing pages may now share a URL.
When two or more pages in the wiki have the same URL, only the page that was created first will be visible to the public. In this case, the visible page should be modified to include any content exclusive to the conflicting pages.
The table URLs with Page Conflicts lists conflicting pages. Click 'Edit' next to any URL to modify its pages.
URLS with page conflicts.jpg
The Edit Conflicting Pages form shows the article text of each page that shares the selected URL, but it can't be edited here.
In order to edit the live page, use the "Edit Live Page" link. Once the live page is up to date, use the form to delete the other pages.
Editing coflicting pages.jpg
In some cases, you may actually want to delete the Live page instead. For example, if one of the other pages is part of a book or has a significant number of revisions, you may want to keep that one.
Editing conflicting pages 2.jpg
To keep all of the pages, you would have to rename them all. Using the "Edit Live Page" link, change the title of the live article. Repeat this process until there is no longer a conflict.