PHP Fatal error:  Uncaught exception 'MongoDB\Driver\Exception\RuntimeException' with message 'SCRAM Failure: invalid salt length of 0 in sasl step2' in /var/www/html/mongo/vendor/mongodb/mongodb/src/Operation/Find.php:219
Stack trace:
#0 /var/www/html/mongo/vendor/mongodb/mongodb/src/Operation/Find.php(219): MongoDB\Driver\Server->executeQuery('uatdata...', Object(MongoDB\Driver\Query), Object(MongoDB\Driver\ReadPreference))
#1 /var/www/html/mongo/vendor/mongodb/mongodb/src/Operation/FindOne.php(105): MongoDB\Operation\Find->execute(Object(MongoDB\Driver\Server))
#2 /var/www/html/mongo/vendor/mongodb/mongodb/src/Collection.php(559): MongoDB\Operation\FindOne->execute(Object(MongoDB\Driver\Server))
#3 /var/www/html/mongo/index.php(50): MongoDB\Collection->findOne(Array, Array)
#4 {main}
  thrown in /var/www/html/mongo/vendor/mongodb/mongodb/src/Operation/Find.php on line 219

    <?php
    $server = 'mongodb://uat-a:27017,uat-b:27017,uat-c:27017';
    $options = [
        'replicaSet' => 'rs-uat',
        'username' => 'CN=my-user,OU=user,O=NA,L=Place,ST=State,C=GB',
        'authMechanism' => 'MONGODB-X509',
        'authSource' => '$external',
        'ssl' => true,
        'connect' => true,
    ];
    $driverOptions = [
        'context' => stream_context_create(
            [
                'ssl' => [
                    'local_cert' => '/etc/local-cert.pem',
                    'cafile' => '/etc/cafile.pem',
                ],
            ]
        ),
    ];
    $database = 'uatdata';

    $client = new MongoDB\Client($server, $options, $driverOptions);
    $db = $client->selectDatabase($database);

    $doc = $db->selectCollection('errors')->findOne([], ['projection' => ['timestamp' => 1, 'uri' => 1]]);