Type 'System.Data.DataTable, System.Data, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' is not allowed here.

<?xml version="1.0"?>
<configuration>
  <configSections>  
        <sectionGroup name="system.data.dataset.serialization" type="System.Data.SerializationSettingsSectionGroup, System.Data, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
            <section name="allowedTypes" type="System.Data.AllowedTypesSectionHandler, System.Data, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>
        </sectionGroup>
    </configSections>
    <system.data.dataset.serialization>
        <allowedTypes>
            <!-- <add type="assembly qualified type name" /> -->
            <add type="System.Data.DataTable, System.Data, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
            <!-- additional <add /> elements as needed -->
        </allowedTypes>
    </system.data.dataset.serialization>
</configuration>