WCF errors translation

If you get a message from server:

The exception message is 'The incoming message has an unexpected message format 'Raw'. The expected message formats for the operation are 'Xml', 'Json'. This can be because a WebContentTypeMapper has not been configured on the binding. See the documentation of WebContentTypeMapper for more details.'. See server logs for more details

this may mean that your ajax client did not set up ContentType such as "application/json; charset=utf-8"