添加WCF服务引用时，HTTP请求被禁止，客户端身份验证方案“匿名”错误

I am having an issue when trying to add a service reference to my winforms app. Both the service and the app are in the same solution and the service is using iisexpress with the default iisexpress development certificate installed. When I try to add the service reference I get the normal dialogs which find the service and then tell me the certificate is not signed by an authority. I "Ok" that message but then I get this error.I am having an issue when trying to add a servi