Card Space exception: incoming policy failed validation

One possibility is that your binding does not contains required claim types. In your client binding, make sure you have at least one required claims:

WSFederationHttpBinding

binding = new WSFederationHttpBinding( WSFederationHttpSecurityMode.Message );

// the required claim sections

binding.Security.Message.ClaimTypeRequirements.Add( new ClaimTypeRequirement( ClaimTypes.Name ) );

// the optional claim sections

binding.Security.Message.ClaimTypeRequirements.Add(

new ClaimTypeRequirement( ClaimTypes.Gender, true ) );

Hope this helps