title: HTTP response body downcast to text/plain if string object
body: <p>Given a string response</p>
  <pre><code>return (ActionResult)new OkObjectResult($&quot;Hello, {name}&quot;)
  </code></pre>
  <p>In v3 this will be downcast to <code>&quot;content-type = text/plain&quot;</code> when <code>&quot;accept /&quot;</code> is requested. In earlier versions this will default to <code>&quot;content-type = application/json&quot;</code></p>
  <p>Now the response body is <code>Hello, {name}</code> instead of <code>&quot;Hello {name}&quot;</code>.</p>
  <p>This can upset brittle client code that assumes JSON will be returned.</p>
  <p>If the accept header is set to <code>&quot;application/json&quot;</code> the response matches the request.</p>
  <p>Is it possible to prefer JSON over text if no preference is stated?</p>