1. Application Octet Stream

I'm guessing here since you didn't show how you defined your endpoint, but I'm pretty sure it's the case. Your endpoint is not defined for web consumption - it's likely using basicHttpBinding. To consume the endpoint via jQuery (or other web/REST clients in general) you need to define an endpoint with the WebHttpBinding, and apply the WebHttpBehavior to it. There are different ways to define the endpoint correctly. The easiest one is to use the WebServiceHostFactory in your.svc file: UserService.svc: <%@ ServiceHost Language='C#' Debug='true' Service='YourNamespace.UserService' Factory='System.ServiceModel.Activation.WebServiceHostFactory'%. For anyone who lands here by searching: 'content type 'application/json; charset=utf-8' was not the expected type 'text/xml; charset=utf-8' A similar error was caused in my case by building and running a service without proper attributes.

UTF8 file is an Unicode UTF8 Encoded Text Document. UTF-8 is a standard transformation format for Unicode characters and it is ideal character repertoire for any platform or language anywhere in the world. Dealing with inconsistent or corrupt character encodings Dealing with inconsistent or corrupt character encodings. ISO 8859-1 also known as Latin-1, or UTF-8) cause any problems. Unfortunately, there does not exist any gold standard for encodings. The closest to such a gold standard, particularly for western languages, is UTF-8. The same applies to UTF-8 (and head would display that since your terminal may be set to UTF-8 encoding, and it would not care about a BOM). If the file is UTF-16, your terminal would display that using head because most of the characters would be ASCII (or even Latin-1), making the 'other' byte of the UTF-16 characters a null.

Application Octet Stream

I got this error message when I tried to update the service reference in my client application. It was resolved when I correctly applied '[DataContract]' and '[DataMember]' attributes to my custom classes. Edit: This would most likely be applicable if your service was set up and working and then it broke after you edited it.