title: How to fix one or more indexers are invalid error in Magento?
body: <p>I'm getting an error in Magento:</p>
  <blockquote>
  <p>One or more indexers are invalid</p>
  </blockquote>
  <p>I tried this in the command prompt:</p>
  <pre><code>php bin/magento indexer:reindex
  </code></pre>
  <p>but when I do, I get this error:</p>
  <p><a href="https://i.stack.imgur.com/osTPm.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/osTPm.png" alt="enter image description here" /></a></p>
  <p>I'm not familiar with Windows; I'm used to working on a Ubuntu terminal.</p>
  <p>please check the Magento dashboard error below:
  <a href="https://i.stack.imgur.com/pslA8.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/pslA8.png" alt="enter image description here" /></a></p>