Fatal error: Uncaught Error: Call to undefined function mb_strtolower() in /home/swanda/public_html/wp-content/mu-plugins/endurance-page-cache.php:374
Stack trace:
#0 /home/swanda/public_html/wp-content/mu-plugins/endurance-page-cache.php(498): Endurance_Page_Cache->to_snake_case('YoastMigrations...')
#1 /home/swanda/public_html/wp-includes/class-wp-hook.php(324): Endurance_Page_Cache->option_handler('yoast_migration...', Array, Array)
#2 /home/swanda/public_html/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters('', Array)
#3 /home/swanda/public_html/wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#4 /home/swanda/public_html/wp-includes/option.php(900): do_action('updated_option', 'yoast_migration...', Array, Array)
#5 /home/swanda/public_html/wp-content/plugins/wordpress-seo/src/config/migration-status.php(174): update_option('yoast_migration...', Array)
#6 /home/swanda/public_html/wp-content/plugins/wordpress-seo/src/config/migration-status.php(127): Yoast\WP\SEO\Config\Migration_Status->set_migration_st in /home/swanda/public_html/wp-content/mu-plugins/endurance-page-cache.php on line 374