Access Chatter Answers in Force.com sites
|Knowledge Article Number||000171249|
|Description||You can not navigate directly to a standard Chatter Answers URL from a Force.com site.
Standard Chatter Answers URLs are not supported when logged into a Force.com Site. This is by design.
Navigate to Chatter Answers
To access Chatter Answers in a Force.com site, you will need to create a Visualforce page using <chatteranswers:allfeeds>.