Catchable fatal error: Argument 1 passed to Joomla\Utilities\ArrayHelper::sortObjects() must be of the type array, boolean given, called in C:\xampp\htdocs\websdis2015new\components\com_content\models\category.php on line 462 and defined in C:\xampp\htdocs\websdis2015new\libraries\vendor\joomla\utilities\src\ArrayHelper.php on line 474