Damaged Master Page Link in SharePoint
There are occasions when the master page that is attached to a site is not valid. The master page connection is made with a URL, and if that URL isn’t valid, you will get errors like:
- File not found (This is SharePoint saying that the master page itself is not found.)
- / cannot be opened (or the like)
- etc.
One quick check you can do is to go to the Site Settings page to check the master page connection. Do this by hacking the URL to point to:
Once there, you can set the master page something valid and your site will miraculously be back in business.