Fatal error: Uncaught Error: Call to undefined function _system_rebuild_theme_data() in /var/www/html/includes/theme.inc:798 Stack trace: #0 /var/www/html/includes/theme.maintenance.inc(57): list_themes() #1 /var/www/html/includes/bootstrap.inc(2589): _drupal_maintenance_theme() #2 /var/www/html/includes/errors.inc(179): drupal_maintenance_theme() #3 /var/www/html/includes/bootstrap.inc(2349): _drupal_log_error(Array, true) #4 [internal function]: _drupal_exception_handler(Object(PDOException)) #5 {main} thrown in /var/www/html/includes/theme.inc on line 798