Fatal error: Uncaught TypeError: APP\publicationFormat\PublicationFormatDAO::getById(): Return value must be of type APP\publicationFormat\PublicationFormat, null returned in /home/u117070472/domains/elcolegiodemorelos.edu.mx/public_html/editorial/classes/publicationFormat/PublicationFormatDAO.php:58 Stack trace: #0 /home/u117070472/domains/elcolegiodemorelos.edu.mx/public_html/editorial/classes/publicationFormat/PublicationFormatDAO.php(174): APP\publicationFormat\PublicationFormatDAO->getById() #1 /home/u117070472/domains/elcolegiodemorelos.edu.mx/public_html/editorial/pages/catalog/CatalogBookHandler.php(351): APP\publicationFormat\PublicationFormatDAO->getByBestId() #2 [internal function]: APP\pages\catalog\CatalogBookHandler->download() #3 /home/u117070472/domains/elcolegiodemorelos.edu.mx/public_html/editorial/lib/pkp/classes/core/PKPRouter.php(334): call_user_func() #4 /home/u117070472/domains/elcolegiodemorelos.edu.mx/public_html/editorial/lib/pkp/classes/core/PKPPageRouter.php(277): PKP\core\PKPRouter->_authorizeInitializeAndCallRequest() #5 /home/u117070472/domains/elcolegiodemorelos.edu.mx/public_html/editorial/lib/pkp/classes/core/Dispatcher.php(165): PKP\core\PKPPageRouter->route() #6 /home/u117070472/domains/elcolegiodemorelos.edu.mx/public_html/editorial/lib/pkp/classes/core/PKPApplication.php(388): PKP\core\Dispatcher->dispatch() #7 /home/u117070472/domains/elcolegiodemorelos.edu.mx/public_html/editorial/index.php(21): PKP\core\PKPApplication->execute() #8 {main} thrown in /home/u117070472/domains/elcolegiodemorelos.edu.mx/public_html/editorial/classes/publicationFormat/PublicationFormatDAO.php on line 58