title: Rails couldn't find a valid model for Preferences association
body: <p>I'm trying to add new record to my DB, but I got this error:
  <a href="https://i.stack.imgur.com/GJDDT.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/GJDDT.png" alt="enter image description here" /></a></p>
  <p>This is my schema.rb:
  <a href="https://i.stack.imgur.com/sS6sY.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/sS6sY.png" alt="enter image description here" /></a></p>
  <p>And this is my method create:
  <a href="https://i.stack.imgur.com/8Gvjt.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/8Gvjt.png" alt="enter image description here" /></a></p>
  <p>And this is my form to add a new record:</p>
  <p><a href="https://i.stack.imgur.com/yz8WM.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/yz8WM.png" alt="enter image description here" /></a></p>
  <p>The param is sending correctly, but when I click on Upload button, nothing is happen, and if I try to add the record from the rails console, I got the error of the first image. I'm a new dev of RoR, someone can help me please?, Thanks!!</p>