Symptom
When you attempt to start Web Sharing, the status indicates "Web Sharing Starting up...", but the Web Sharing does not start up.
You may also notice this text in your Console log:
dyld: /usr/sbin/httpd Undefined symbols:
_apple_hfs_module
/usr/sbin/apachectl start: httpd could not be started
Solution
This issue is caused by an entry in the configuration file for the Apache Web server. Editing this file allows Web Sharing to start up.
To make this change, follow these steps:
1. Open the Terminal (/Applications/Utilities/).
2. At the prompt (#), type:
sudo pico /etc/httpd/httpd.conf
3. Press Return.
4. Enter your Admin user password and press Return.
5. While pressing the Control key, press the "W" key.
6. Type: libexec/httpd/mod_hfs_apple.so
7. Press Return. You should now see the line:
LoadModule apple_hfs_module libexec/httpd/mod_hfs_apple.so
8. Change the line to read:
LoadModule hfs_apple_module libexec/httpd/mod_hfs_apple.so
9. While pressing the Control key, press the "X" key.
10. Press the "Y" key.
11. Press Return.
12. Quit the Terminal.
You should now be able open System Preferences and successfully start Web Sharing.