If the client login screen shows an error relating to the coding service, you won't be able to see much information, due to security preventing the information being shown to a remote device (the error information could conceivably help an attacker). The way to see the information is to open the service URL in a browser running on the server that is hosting the coding service. It will then be displayed in the browser window.

The service URL is displayed in the coding login screen error information and takes the form:

http://<server>/<application>/PostCodingService.svc

For example:

http://myservername/PostCodingService/PostCodingService.svc

Enter this URL into the browser address.