Warning: mysqli_connect(): Error while reading greeting packet. PID=28450 in includes/mysqli.php on line 22

Warning: mysqli_connect(): (HY000/2006): MySQL server has gone away in includes/mysqli.php on line 22

Warning: mysqli_error() expects parameter 1 to be mysqli, bool given in includes/mysqli.php on line 70
Error
Cannot establish a database connection.
MySQL returns the error . (It's possible that the web host's database is currently down, if so this is a temporary error and will go away when the database is accessible again.)