I'm not sure if this validation tool verifies configuration files.
Check your machine.config (Windows\Microsoft.NET\Framework\v2.0.50727\CONFIG\machine.config or something like this).
Try adding something like this to the configSections section.
<sectionGroup name="system.serviceModel" type="System.ServiceModel.Configuration.ServiceModelSectionGroup, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
<section name="behaviors" type="System.ServiceModel.Configuration.BehaviorsSection, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>
<section name="bindings" type="System.ServiceModel.Configuration.BindingsSection, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>
<section name="client" type="System.ServiceModel.Configuration.ClientSection, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>
<section name="comContracts" type="System.ServiceModel.Configuration.ComContractsSection, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>
<section name="commonBehaviors" type="System.ServiceModel.Configuration.CommonBehaviorsSection, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" allowDefinition="MachineOnly" allowExeDefinition="MachineOnly"/>
<section name="diagnostics" type="System.ServiceModel.Configuration.DiagnosticSection, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>
<section name="extensions" type="System.ServiceModel.Configuration.ExtensionsSection, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>
<section name="machineSettings" type="System.ServiceModel.Configuration.MachineSettingsSection, SMDiagnostics, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" allowDefinition="MachineOnly" allowExeDefinition="MachineOnly"/>
<section name="serviceHostingEnvironment" type="System.ServiceModel.Configuration.ServiceHostingEnvironmentSection, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>
<section name="services" type="System.ServiceModel.Configuration.ServicesSection, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>
</sectionGroup>
Or this: http://www.dotnettech.net/BCL/Article.aspx...0%2f430270.aspx