A timeout occured after 30000ms selecting a server using CompositeServerSelector

I try to deploy my mongo database in mongolabs , everything works fine,

and i create a new database in mongo labs, Please see my connectionstring.

    public DbHelper()
    {

        MongoClientSettings settings = new MongoClientSettings()
        {
            Credentials = new MongoCredential[] { MongoCredential.CreateCredential("dbname", "username", "password") },
            Server = new MongoServerAddress("ds011111.mongolab.com", 11111),
            //ConnectTimeout = new TimeSpan(30000)
        };

        Server = new MongoClient(settings).GetServer();

        DataBase = Server.GetDatabase(DatabaseName);

    }

but when i try to connet the database it's shows error like

Could you please give a advice.

Thanks