A common error that could appear after you install prestashop is
Fatal error: Declaration of AdminLoginControllerCore::viewAccess() must be compatible with AdminControllerCore::viewAccess($disable = false) in /var/www/prestashop/controllers/admin/AdminLoginController.php on line 27
or, if you haven’t set prestashop into dev mode, you’ll get a 500 error.
Go to ROOT/controllers\admin\AdminLoginController.php at line 153 you’ll have to change *public function viewAccess() to public function viewAccess($disable = false)
Thanks to https://stuffweb2016.wordpress.com/2018/08/26/prestashop-1-6-x-admin-error-500/