title: Warning: DOMXPath::query(): Invalid expression in /opt/lampp/htdocs/magento/vendor/magento/framework/Config/Dom.php on line 273
body: <p>I am using Magento latest release 2.x.</p>
  
  <p>Everything works fine, except when saving a product with an image Magento 2.x throws an error </p>
  
  <blockquote>
    <p>Warning: DOMXPath::query(): Invalid expression in /opt/lampp/htdocs/magento/vendor/magento/framework/Config/Dom.php on line 273</p>
  </blockquote>
  
  <p>I have just started learning Magento. any help would be appreciated.</p>