The way you invoke service methods has changed a little. The new signature looks like this: invoke = function(url, methodName, params, onMethodComplete, onMethodTimeout, onMethodError, onMethodAborted, userContext, timeoutInterval, priority, useGetMethod) Therefore, you should try to change 'Sys.Net.ServiceMethodRequest.callMethod(_serviceURL, _serviceMethod, null, _onMethodComplete, null, null, [this]);' into 'Sys.Net.ServiceMethod.invoke(_serviceURL, _serviceMethod, null, _onMethodComplete, null