title: Error: Unknown command: cask || despite the use of multiple instance trials
body: <p>I am not able to do anything anymore. I keep getting the error <code>Error: Unknown command: cask</code> even though I have previously used a lot of different installations from this link: <a href="https://stackoverflow.com/questions/30413621/homebrew-cask-option-not-recognized">Homebrew cask option not recognized?</a></p>
  <p><strong>NONE OF THEM HELPED!</strong></p>
  <p>For example I get this output:</p>
  <p><a href="https://i.stack.imgur.com/iWbOu.png" rel="noreferrer"><img src="https://i.stack.imgur.com/iWbOu.png" alt="enter image description here" /></a></p>
  <p>After the instance I want to apply this command: <code>brew cask install cscreen</code> to then go to <code>cscreen -l</code>. However, I keep getting the above error...</p>
  <p>Please help.
  I want to use this because without it I am not able to work on a closed MacBook because when I close the monitor it goes back to the dreaded setting of 75Hz.</p>
  <p>Regards!</p>