WCF - Send Secured Messages and Receive Unsecured Responses

When WS-Security is enabled, WCF expect the response has the same encryption & signing requirements as the request. If the server returns an unsecured response message or SOAP fault, WCF will throw the MessageSecurityException.

To resolve this, you can get a hotfix from Microsoft, http://support.microsoft.com/kb/971493/

After the hotfix is applied, all you have to do is to set the new EnableUnsecuredResponse attribute to true.

NOTE: It only works with CustomBinding.