I know this is old but since I found a solution after looking here I thought I should provide an answer. VS 11 holds the publishing app_offline.htm file in this location: C:\Users\[user]\AppData\Roaming\Microsoft\VisualStudio\11.0\app_offline.htm I have tested this and customized it and it does work if you change this file. The down side, of course, is that … Read more
As someone also commented, Facebook has offered alternatives. https://developers.facebook.com/docs/roadmap/completed-changes/offline-access-removal
I have used the extremely handy app_offline.htm trick to shut down/update sites in the past without any issues. Be sure that you are actually placing the “app_offline.htm” file in the “root” of the website that you have configured within IIS. Also ensure that the file is named exactly as it should be: app_offline.htm Other than … Read more