Currently Being ModeratedFeb 26, 2013 11:00 PM (in response to James Rothschild)
It means the files have the wrong owner so the OS won't let the server access them. The launchd daemon keeps on trying every 10 seconds to start up the webapp but can't because file permissions are wrong.
Apache by default runs as user www or _www, but installed files would usually have ownership by user root. User root is a tighter security user than www, so the files are blocked by the OS. All the relevant files and folders need to be accessible to Apache for the webapp to work.
The easiest way to do this is to simply set all folders and files to world readable, and some files need to be world writable if databases need to be written to. However this solution may be insecure for an internet-facing server. It is however expedient and a good tool for diagnosis.
You should lso look at the error.log for the domain for more information. There's also a setting to have Apache write a startup.log at every startup, but it is not active in the default configuration.