Several problem in php error_log file

[@diegofrancesco]

Hello,
I checked the error_log file and I found several php notice and error but I don't understand how to fix it. The shop work properly. How can I do?

PHP Fatal error:  Uncaught exception 'Exception' with message 'Invalid SortOrder direction `asc?order=product`. Expecting one of: `ASC`, `DESC`, or `RANDOM`.' in /home/ic28oglm/public_html/src/Core/Product/Search/SortOrder.php:117

PHP Notice:  Undefined index: nb_products in /home/ic28oglm/public_html/controllers/front/listing/ManufacturerController.php on line 186

PHP Notice:  Trying to get property of non-object in /home/ic28oglm/public_html/vendor/prestashop/smarty/sysplugins/smarty_internal_templatebase.php(157) : eval()'d code on line 197
PHP Warning:  htmlspecialchars() expects parameter 1 to be string, array given in /home/ic28oglm/public_html/vendor/prestashop/smarty/sysplugins/smarty_internal_templatebase.php(157) : eval()'d code on line 206

PS version 1.7.2.4
PHP version 5.6.33