No suitable servers found (`serverSelectionTryOnce` set): [connection refused calling hello on 'lin2-vlan:27017']

error: 13053
file: /var/www/html/trans4men-www/libs/composer/vendor/alcaeus/mongo-php-adapter/lib/Alcaeus/MongoDbAdapter/ExceptionConverter.php
line: 85

{
    "file": "/var/www/html/trans4men-www/libs/composer/vendor/alcaeus/mongo-php-adapter/lib/Mongo/MongoCollection.php",
    "line": 403,
    "function": "toLegacy",
    "class": "Alcaeus\\MongoDbAdapter\\ExceptionConverter",
    "type": "::"
}

{
    "file": "/var/www/html/trans4men-www/class/Tools/Session.php",
    "line": 67,
    "function": "update",
    "class": "MongoCollection",
    "type": "->"
}

{
    "file": "/var/www/html/trans4men-www/class/Tools/Session.php",
    "line": 14,
    "function": "affiliation_generate",
    "class": "Tools_Session",
    "type": "::"
}

{
    "file": "/var/www/html/trans4men-www/__webui.php",
    "line": 178,
    "function": "initialize",
    "class": "Tools_Session",
    "type": "::"
}

{
    "file": "/var/www/html/trans4men-www/__catchall.php",
    "line": 3,
    "args": [
        "/var/www/html/trans4men-www/__webui.php"
    ],
    "function": "include_once"
}