Warning: mysqli_real_connect()... How to fix?

Question

PHP

Error after updating WordPress template:
Warning: mysqli_real_connect(): (HY000/2002): No such file or directory in /home/all-remont/data/www/all-remont.ru/wrdprss/wp-includes/wp- db.php on line 1489
Line 1489 has this code:

mysqli_real_connect( $this->dbh, $host, $this->dbuser, $this->dbpassword, null, $port, $socket, $client_flags );

and then a few if
How to fix the error?
Website: www.all-remont.ru/wrdprss

Answer 1

this is mysqli_real_connect database connection error