nhibernate has invalid child element 'add'

Question

I'm having issues running my application where it uses NHibernate. The runtime issue I'm getting is:

The element 'session-factory' in namespace 'urn:nhibernate-configuration-2.2' has invalid child element 'add' in namespace 'urn:nhibernate-configuration-2.2'. List of possible elements expected: 'property, mapping, class-cache, collection-cache, event, listener' in namespace 'urn:nhibernate-configuration-2.2'.

My code is:

protected void Initialization(Assembly[] assemblies, string fileName)
{
    logger.DebugFormat( @"Initialization Start {0:HH:mm:ss.fff}", DateTime.Now );

    SessionFactory = Fluently
        .Configure(
            new Configuration()
                .Configure( fileName )
        )
        .Mappings( x => assemblies
            .ForEach( a => x
                .FluentMappings
                .AddFromAssembly( a )
                .Conventions
                .Add(
                    AutoImport.Never(),
                    DefaultCascade.All(),
                    DefaultLazy.Always(),
                    ForeignKey.EndsWith( "Id" ),
                    PrimaryKey.Name.Is( c => c.EntityType.Name + "Id" ),
                    Table.Is( c => "[" + c.EntityType.Name + "]" )
                )
            )
        )
        .BuildSessionFactory();

    logger.DebugFormat( @"Initialization Finish {0:HH:mm:ss.fff}", DateTime.Now );
}

I already installed Full-Text and Semantic Extractions for Search, but it didn't fix my issue.

Contents of the filename:

<?xml version='1.0' encoding='utf-8'?>
<hibernate-configuration xmlns="urn:nhibernate-configuration-2.2">
    <session-factory>
        <property name="connection.provider">NHibernate.Connection.DriverConnectionProvider</property>
        <property name="connection.driver_class">NHibernate.Driver.SqlClientDriver</property>
        <add name="CoreDbContext" connectionString="Data Source=(localdb)\\mssqllocaldb;Initial Catalog=Database_name;Integrated Security=True;MultipleActiveResultSets=True" providerName="System.Data.SqlClient"/>
        <property name="show_sql">true</property>
        <property name="dialect">NHibernate.Dialect.MsSql2008Dialect</property>
    </session-factory>
</hibernate-configuration>

Answer 1

connectionstring is configured like the other properties

<?xml version='1.0' encoding='utf-8'?>
<hibernate-configuration xmlns="urn:nhibernate-configuration-2.2">
    <session-factory>
        <property name="connection.provider">NHibernate.Connection.DriverConnectionProvider</property>
        <property name="connection.driver_class">NHibernate.Driver.SqlClientDriver</property>
        <property name="connection.connection_string">Data Source=(localdb)\\mssqllocaldb;Initial Catalog=Database_name;Integrated Security=True;MultipleActiveResultSets=True</property>
        <property name="show_sql">true</property>
        <property name="dialect">NHibernate.Dialect.MsSql2008Dialect</property>
    </session-factory>
</hibernate-configuration>