Fatal error: Uncaught Error: Call to undefined function _wp_can_use_pcre_u() in /var/www/html/wp-includes/utf8.php:137
Stack trace:
#0 /var/www/html/wp-settings.php(114): require()
#1 /var/www/html/wp-config.php(139): require_once('/var/www/html/w...')
#2 /var/www/html/wp-load.php(50): require_once('/var/www/html/w...')
#3 /var/www/html/wp-blog-header.php(13): require_once('/var/www/html/w...')
#4 /var/www/html/index.php(17): require('/var/www/html/w...')
#5 {main}
  thrown in /var/www/html/wp-includes/utf8.php on line 137