Did you migrate from managed wp to unmanaged? Check this page
https://ru.godaddy.com/help/move-a-managed-wordpress-site-to-an-unmanaged-wordpress-account-19798
In the site directory, locate the /wp-content/mu-plugins/ directory, and delete the gd-system-plugin and gd-system-plugin.php files.
In the wp-config.php file, find and remove the reference to gd-config.php. The sample code below from the wp-config.php file shows the general location of the line to delete.