title: Presta Shop errors on registration
body: <p>recently I made SEO optimization for client of mine, and I had to change some things on the server, like use PHP 7 and in Presta Shop admin panel to enable caching and SEO links.
  I don`t use Presta Shop and I am not familiar with it, but some of this changes broke something in the code.
  When new user tries to registrate it gets that error :</p>
  
  <pre><code>Fatal error: Uncaught Error: Access to undeclared static property: Validate::$data in /home/unikalna/public_html/classes/ObjectModel.php:1032 Stack trace: #0 /home/unikalna/public_html/controllers/front/AuthController.php(406): ObjectModelCore-&gt;validateController() #1 /home/unikalna/public_html/controllers/front/AuthController.php(252): AuthControllerCore-&gt;processSubmitAccount() #2 /home/unikalna/public_html/classes/controller/Controller.php(171): AuthControllerCore-&gt;postProcess() #3 /home/unikalna/public_html/classes/Dispatcher.php(373): ControllerCore-&gt;run() #4 /home/unikalna/public_html/index.php(28): DispatcherCore-&gt;dispatch() #5 {main} thrown in /home/unikalna/public_html/classes/ObjectModel.php on line 1032
  </code></pre>
  
  <p>And also if its already registered and tries to buy something.</p>
  
  <p>Version :PrestaShop™ 1.6.0.6 </p>
  
  <p><strong>Solved : Presta Shop 1.6 don`t work with PHP 7</strong> </p>