title: prestashop 1.6, css files isn't loaded in back-office
body: <p>After charged project into server, css files isn't loaded in back-office,despite I emptied the cache, but in front-office all things is nice.</p>
  
  <p>css files i need to load is admin-theme.css and overrides.css. they exist in<br>
  \admin-xxx\themes\default\css folder .</p>