title: Rails production getting 422 error (The change you wanted was rejected)
body: <p>I'm running a Rails production in digital ocean droplet. I can load the static pages, but whenever a controller action (like <code>create</code>, <code>signin</code>, <code>signup</code>) occurs, the server raises a "The change you wanted was rejected." error.
  Does anyone know why this happens?</p>
  
  <p>I can add data through console but cannot through the application.</p>