Below is a list of HTTP Response codes and their meaning.
This information was obtained from:
HTTP Response Code Definitions
Method Not Allowed
Proxy Authentication Required
Request Entity Too Large
Request-URI Too Large
Unsupported Media Type
Requested range not satisfiable
Internal Server Error
HTTP Version not supported
It would be useful to obtain information on HTTP response headers. If you are using Mozilla Firefox, you can download an 'add-ons' (extension) called LiveHTTPHeaders which will allow you to capture this information. If you are using Internet Explorer, you can use DebugBar instead.
For Live HTTP Headers, please do the following:
Now try accessing the Confluence main page and all HTTP request headers, cookies descriptions (such as the seraph authentication 'seraph.os.cookie') will be logged in the pop-up window. Please save this information in a text file, use the 'Save All' option.
Run the downloaded installation file. After installing the DebugBar, the toolbar should automatically display on the next IE startup. If not, you might need to show the toolbar in IE by clicking on View > Explorer Bar then select DebugBar