Fatal error: Uncaught TypeError: Argument 1 passed to WP_Translation_Controller::set_locale() must be of the type string, null given, called in /web/htdocs6/ondrejbecickacz/home/subdoms/test3/wp-includes/l10n.php on line 803 and defined in /web/htdocs6/ondrejbecickacz/home/subdoms/test3/wp-includes/l10n/class-wp-translation-controller.php:87 Stack trace: #0 /web/htdocs6/ondrejbecickacz/home/subdoms/test3/wp-includes/l10n.php(803): WP_Translation_Controller->set_locale(NULL) #1 /web/htdocs6/ondrejbecickacz/home/subdoms/test3/wp-content/plugins/polylang/include/olt-manager.php(115): load_textdomain('mailpoet', '/web/htdocs6/on...') #2 /web/htdocs6/ondrejbecickacz/home/subdoms/test3/wp-includes/class-wp-hook.php(326): PLL_OLT_Manager->load_textdomains(NULL) #3 /web/htdocs6/ondrejbecickacz/home/subdoms/test3/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters(NULL, Array) #4 /web/htdocs6/ondrejbecickacz/home/subdoms/test3/wp-includes/plugin.php(517): WP_Hook->do_action(Array) #5 /web/htdocs6/ondrejbecickacz/home/subdom in /web/htdocs6/ondrejbecickacz/home/subdoms/test3/wp-includes/l10n/class-wp-translation-controller.php on line 87

Fatal error: Uncaught TypeError: Argument 1 passed to WP_Translation_Controller::set_locale() must be of the type string, null given, called in /web/htdocs6/ondrejbecickacz/home/subdoms/test3/wp-includes/l10n.php on line 803 and defined in /web/htdocs6/ondrejbecickacz/home/subdoms/test3/wp-includes/l10n/class-wp-translation-controller.php:87 Stack trace: #0 /web/htdocs6/ondrejbecickacz/home/subdoms/test3/wp-includes/l10n.php(803): WP_Translation_Controller->set_locale(NULL) #1 /web/htdocs6/ondrejbecickacz/home/subdoms/test3/wp-includes/l10n.php(957): load_textdomain('default', '/web/htdocs6/on...', NULL) #2 /web/htdocs6/ondrejbecickacz/home/subdoms/test3/wp-includes/class-wp-fatal-error-handler.php(49): load_default_textdomain() #3 [internal function]: WP_Fatal_Error_Handler->handle() #4 {main} thrown in /web/htdocs6/ondrejbecickacz/home/subdoms/test3/wp-includes/l10n/class-wp-translation-controller.php on line 87