invalid argument supplied foreach()…..wp-includes/users.php line 721

I have been having this error for about 5 days now, i have tried everything to fix it and i just can’t. This error just appeared randomly and won’t go away i even backed up my database, deleted all of my WordPress files then put in brand new word press files then re uploaded my database and the error came back!

heres the section of coding with my error

/**
 * Unserialize user metadata, fill $user object, then cache everything.
 *
 * @since 3.0.0
 * @param object $user The User object.
 * @param array $metavalues An array of objects provided by get_user_metavalues()
 */
function _fill_single_user( &$user, &$metavalues ) {
	global $wpdb;

Line 721: foreach ( $metavalues as $meta ) {
		$value = maybe_unserialize($meta->meta_value);
		// Keys used as object vars cannot have dashes.
		$key = str_replace('-', '', $meta->meta_key);
		$user->{$key} = $value;
	}

Has anyone else ever had this error, can anyone help me?