Multisite network issue

Hello,

After login to the WordPress admin, i am getting this error.

Notice: Undefined variable: current_user in /var/www/vhosts/instantupskill.com/httpdocs/wp-content/mu-plugins/allow-network-user-edits.php on line 181

Notice: Trying to get property ‘ID’ of non-object in /var/www/vhosts/instantupskill.com/httpdocs/wp-content/mu-plugins/allow-network-user-edits.php on line 181

Notice: has_cap was called with an argument that is deprecated since version 2.0.0! Usage of user levels is deprecated. Use capabilities instead. in /var/www/vhosts/instantupskill.com/httpdocs/wp-includes/functions.php on line 4782

LINE NUMBER 181 TO 182 IS:

if (is_super_admin( $current_user->ID )) {
add_submenu_page( “users.php”, “User Editing”, “User Editing”, “manage_options”, “allow-network-user-edits”, array(“allowNetworkUserEdits”, “get_admin_page”));

and the line number 4782 in functions.php is:

trigger_error( sprintf( __( ‘%1$s was called with an argument that is deprecated since version %2$s! %3$s’ ), $function, $version, $message ) );