Symptom
If you have modified preinstalled items (such as a symlink) at /Library/WebServer/Documents, then you may encounter unexpected behavior after installing a Mac OS X Server software update.
Solution
If you have modified preinstalled items in the folder /Library/WebServer/Documents, you should back up the folder as a precaution before installing system software updates.
When Apple releases software updates available for Mac OS X Server, they often include a later version of the Apache Web server and the included online Apache manual. The content for the manual is in the /Library/Documentation/Services/apache/ folder, but by default Apache serves content from /Library/WebServer/Documents/. That folder contains a symbolic link (symlink) pointing to the manual. That symlink and the other files originally installed in that folder, including index.html, are subject to being overwritten in the event of a software update. If you modify them, they are subject to being restored to their original content. Certain changes, such as changing a symlink to a folder, may confuse the update process and result in a new symlink being created with a new name. While it is safe to add files and folders to /Library/WebServer/Documents, be cautious when modifying the preinstalled files and folders.