Мобильная версия для сайта на ModX

Fatal error: Uncaught Error: Call to undefined function twentynineteen_get_discussion_data() in /home/host1369038/burlet-mikhail.ru/htdocs/www/wp-content/themes/BurletTheme/comments.php:24 Stack trace: #0 /home/host1369038/burlet-mikhail.ru/htdocs/www/wp-includes/comment-template.php(1554): require() #1 /home/host1369038/burlet-mikhail.ru/htdocs/www/wp-content/themes/BurletTheme/single.php(76): comments_template() #2 /home/host1369038/burlet-mikhail.ru/htdocs/www/wp-includes/template-loader.php(106): include('/home/host13690...') #3 /home/host1369038/burlet-mikhail.ru/htdocs/www/wp-blog-header.php(19): require_once('/home/host13690...') #4 /home/host1369038/burlet-mikhail.ru/htdocs/www/index.php(17): require('/home/host13690...') #5 {main} thrown in /home/host1369038/burlet-mikhail.ru/htdocs/www/wp-content/themes/BurletTheme/comments.php on line 24