WordPress - Контактная форма

Я перенес сайт Wordpress от старого хостинг-провайдера к другому. Для этого я выполнил следующие шаги:

• Я скачиваю контент public_html у старого провайдера;
• Я экспортировал содержимое базы данных из старого провайдера;
• Я пробовал использовать автоматический импорт WordPress, но он не работает (не удалось установить FTP-соединение со старым провайдером);
• Я установил Wordpress в новом провайдере;
• Я скопировал старую папку public_html в новую;
• Я импортировал все старые таблицы из предыдущего экспорта базы данных;
• Я исправил подключение к базе данных (DB_NAME, DB_USER, DB_PASSWORD, ...) в файле wp-config.php;

На данный момент сайт вроде работает ... но не «Контактная форма». Фактически, после активации режима отладки WordPress, если я отправляю сообщение с сайта, я получаю такой ответ в моем журнале debug.log:

[22-Nov-2018 16:21:12 UTC] PHP Fatal error:  Uncaught Error: Class 'RevSliderFunctionsWP' not found in /home/yc32of0z/public_html/wp-content/plugins/revslider/revslider.php:91
Stack trace:
#0 /home/yc32of0z/public_html/wp-settings.php(305): include_once()
#1 /home/yc32of0z/public_html/wp-config.php(88): require_once('/home/yc32of0z/...')
#2 /home/yc32of0z/public_html/wp-load.php(37): require_once('/home/yc32of0z/...')
#3 /home/yc32of0z/public_html/xmlrpc.php(29): include('/home/yc32of0z/...')
#4 {main}
thrown in /home/yc32of0z/public_html/wp-content/plugins/revslider/revslider.php on line 91
[22-Nov-2018 16:21:34 UTC] PHP Deprecated:  Function create_function() is deprecated in /home/yc32of0z/public_html/wp-content/plugins/LayerSlider/wp/widgets.php on line 4
[22-Nov-2018 16:21:34 UTC] PHP Notice:  Constant DB_NAME already defined in /home/yc32of0z/public_html/wp-content/plugins/revslider/includes/framework/functions-wordpress.class.php on line 19
[22-Nov-2018 16:21:34 UTC] PHP Notice:  Constant DB_USER already defined in /home/yc32of0z/public_html/wp-content/plugins/revslider/includes/framework/functions-wordpress.class.php on line 22
[22-Nov-2018 16:21:34 UTC] PHP Notice:  Constant DB_PASSWORD already defined in /home/yc32of0z/public_html/wp-content/plugins/revslider/includes/framework/functions-wordpress.class.php on line 25
[22-Nov-2018 16:21:34 UTC] PHP Notice:  Constant DB_HOST already defined in /home/yc32of0z/public_html/wp-content/plugins/revslider/includes/framework/functions-wordpress.class.php on line 28
[22-Nov-2018 16:21:34 UTC] PHP Notice:  Constant DB_CHARSET already defined in /home/yc32of0z/public_html/wp-content/plugins/revslider/includes/framework/functions-wordpress.class.php on line 31
[22-Nov-2018 16:21:34 UTC] PHP Notice:  Constant DB_COLLATE already defined in /home/yc32of0z/public_html/wp-content/plugins/revslider/includes/framework/functions-wordpress.class.php on line 34
[22-Nov-2018 16:21:34 UTC] PHP Warning:  require(wp-salt.php): failed to open stream: No such file or directory in /home/yc32of0z/public_html/wp-content/plugins/revslider/includes/framework/functions-wordpress.class.php on line 41
[22-Nov-2018 16:21:34 UTC] PHP Warning:  require(wp-salt.php): failed to open stream: No such file or directory in /home/yc32of0z/public_html/wp-content/plugins/revslider/includes/framework/functions-wordpress.class.php on line 41
[22-Nov-2018 16:21:34 UTC] PHP Fatal error:  require(): Failed opening required 'wp-salt.php' (include_path='.:/opt/alt/php72/usr/share/pear') in /home/yc32of0z/public_html/wp-content/plugins/revslider/includes/framework/functions-wordpress.class.php on line 41
[22-Nov-2018 16:21:59 UTC] PHP Deprecated:  Function create_function() is deprecated in /home/yc32of0z/public_html/wp-content/plugins/LayerSlider/wp/widgets.php on line 4
[22-Nov-2018 16:21:59 UTC] PHP Notice:  Constant DB_NAME already defined in /home/yc32of0z/public_html/wp-content/plugins/revslider/includes/framework/functions-wordpress.class.php on line 19
[22-Nov-2018 16:21:59 UTC] PHP Notice:  Constant DB_USER already defined in /home/yc32of0z/public_html/wp-content/plugins/revslider/includes/framework/functions-wordpress.class.php on line 22
[22-Nov-2018 16:21:59 UTC] PHP Notice:  Constant DB_PASSWORD already defined in /home/yc32of0z/public_html/wp-content/plugins/revslider/includes/framework/functions-wordpress.class.php on line 25
[22-Nov-2018 16:21:59 UTC] PHP Notice:  Constant DB_HOST already defined in /home/yc32of0z/public_html/wp-content/plugins/revslider/includes/framework/functions-wordpress.class.php on line 28
[22-Nov-2018 16:21:59 UTC] PHP Notice:  Constant DB_CHARSET already defined in /home/yc32of0z/public_html/wp-content/plugins/revslider/includes/framework/functions-wordpress.class.php on line 31
[22-Nov-2018 16:21:59 UTC] PHP Notice:  Constant DB_COLLATE already defined in /home/yc32of0z/public_html/wp-content/plugins/revslider/includes/framework/functions-wordpress.class.php on line 34
[22-Nov-2018 16:21:59 UTC] PHP Warning:  require(wp-salt.php): failed to open stream: No such file or directory in /home/yc32of0z/public_html/wp-content/plugins/revslider/includes/framework/functions-wordpress.class.php on line 41
[22-Nov-2018 16:21:59 UTC] PHP Warning:  require(wp-salt.php): failed to open stream: No such file or directory in /home/yc32of0z/public_html/wp-content/plugins/revslider/includes/framework/functions-wordpress.class.php on line 41
[22-Nov-2018 16:21:59 UTC] PHP Fatal error:  require(): Failed opening required 'wp-salt.php' (include_path='.:/opt/alt/php72/usr/share/pear') in /home/yc32of0z/public_html/wp-content/plugins/revslider/includes/framework/functions-wordpress.class.php on line 41
[22-Nov-2018 16:22:35 UTC] PHP Deprecated:  Function create_function() is deprecated in /home/yc32of0z/public_html/wp-content/plugins/LayerSlider/wp/widgets.php on line 4
[22-Nov-2018 16:22:35 UTC] PHP Notice:  Constant DB_NAME already defined in /home/yc32of0z/public_html/wp-content/plugins/revslider/includes/framework/functions-wordpress.class.php on line 19
[22-Nov-2018 16:22:35 UTC] PHP Notice:  Constant DB_USER already defined in /home/yc32of0z/public_html/wp-content/plugins/revslider/includes/framework/functions-wordpress.class.php on line 22
[22-Nov-2018 16:22:35 UTC] PHP Notice:  Constant DB_PASSWORD already defined in /home/yc32of0z/public_html/wp-content/plugins/revslider/includes/framework/functions-wordpress.class.php on line 25
[22-Nov-2018 16:22:35 UTC] PHP Notice:  Constant DB_HOST already defined in /home/yc32of0z/public_html/wp-content/plugins/revslider/includes/framework/functions-wordpress.class.php on line 28
[22-Nov-2018 16:22:35 UTC] PHP Notice:  Constant DB_CHARSET already defined in /home/yc32of0z/public_html/wp-content/plugins/revslider/includes/framework/functions-wordpress.class.php on line 31
[22-Nov-2018 16:22:35 UTC] PHP Notice:  Constant DB_COLLATE already defined in /home/yc32of0z/public_html/wp-content/plugins/revslider/includes/framework/functions-wordpress.class.php on line 34
[22-Nov-2018 16:22:35 UTC] PHP Warning:  require(wp-salt.php): failed to open stream: No such file or directory in /home/yc32of0z/public_html/wp-content/plugins/revslider/includes/framework/functions-wordpress.class.php on line 41
[22-Nov-2018 16:22:35 UTC] PHP Warning:  require(wp-salt.php): failed to open stream: No such file or directory in /home/yc32of0z/public_html/wp-content/plugins/revslider/includes/framework/functions-wordpress.class.php on line 41
[22-Nov-2018 16:22:35 UTC] PHP Fatal error:  require(): Failed opening required 'wp-salt.php' (include_path='.:/opt/alt/php72/usr/share/pear') in /home/yc32of0z/public_html/wp-content/plugins/revslider/includes/framework/functions-wordpress.class.php on line 41
[22-Nov-2018 16:23:35 UTC] PHP Deprecated:  Function create_function() is deprecated in /home/yc32of0z/public_html/wp-content/plugins/LayerSlider/wp/widgets.php on line 4

Может кто-нибудь помочь мне?