Unable to get a compliant ConfigurationRS message for Certification

We have developed the pull seller API integration. Travelgate have no problems with our MetadataRQ, Geographic and HotetList Responses which they have accessed durind our Certification. But we are stuck on ConfigurationRQ now for months … the request / response looks fine to me but the certification process has stalled for the validation of our response which seems so simple and straightforward but we must be doing something wrong. Does anyone have some insight on what may be causing this error:

Ex.ToString:[System.InvalidOperationException: Error en el documento XML (1, 444). —> System.InvalidOperationException: Error de validación de instancia: ‘String’ no es un valor válido para eTypeMetaData

This is the Request being sent to our endpoint:

<?xml version="1.0"?> 
<ConfigurationRQ xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> 
<timeoutMilliseconds>999999</timeoutMilliseconds> 
<source> 
<languageCode>en</languageCode> 
</source> 
<filterAuditData> 
<registerTransactions>true</registerTransactions> 
</filterAuditData> 
<optionsQuota>0</optionsQuota> 
<hubProvider>PPT</hubProvider> 
<hubProviderInstanceCode>GEN2</hubProviderInstanceCode> 
<Configuration> 
<UrlGeneric>https://uat.endpoint.com/services</UrlGeneric> 
<Parameters> 
<Parameter key="UserName" value="company*user" /> 
<Parameter key="Password" value="HELLOWORLD" /> 
</Parameters> 
</Configuration> 
</ConfigurationRQ> 

And this is the error response Travelgate is providing to us.

<?xml version="1.0"?> 
<ConfigurationRS xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> 
<operationImplemented>true</operationImplemented> 
<applicationErrors> 
<type>101</type> 
<description>Ex.ToString:[System.InvalidOperationException: Error en el documento XML (1, 444). ---> System.InvalidOperationException: Error de validación de instancia: 'String' no es un valor válido para eTypeMetaData. 
en Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationReaderConfigurationRS.Read9_eTypeMetaData(String s) 
en Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationReaderConfigurationRS.Read14_ParametersExtendedBase(Boolean isNullable, Boolean checkType) 
en Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationReaderConfigurationRS.Read15_ParametersExtended(Boolean isNullable, Boolean checkType) 
en Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationReaderConfigurationRS.Read16_ConfigurationRS(Boolean isNullable, Boolean checkType) 
en Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationReaderConfigurationRS.Read17_ConfigurationRS() 
--- Fin del seguimiento de la pila de la excepción interna --- 
en System.Xml.Serialization.XmlSerializer.Deserialize(XmlReader xmlReader, String encodingStyle, XmlDeserializationEvents events) 
en System.Xml.Serialization.XmlSerializer.Deserialize(XmlReader xmlReader) 
en Serializers.Xml.DynamicXmlSerializer.UnserializeFromXmlStr(String xml, Type type, XmlReaderSettings xmlReaderSettings, String language) 
en Util.UtilGEN2.<SendRequestAsync>d__14`1.MoveNext() 
--- Fin del seguimiento de la pila de la ubicación anterior donde se produjo la excepción --- 
en System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() 
en System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) 
en System.Runtime.CompilerServices.TaskAwaiter`1.GetResult() 
en XMLTravelgate.Aggregators.Providers.Hotel.GEN2.Manager.GenericAsync`2.<ProcessAsync>d__0.MoveNext() 
--- Fin del seguimiento de la pila de la ubicación anterior donde se produjo la excepción --- 
en System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() 
en System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) 
en System.Runtime.CompilerServices.TaskAwaiter`1.GetResult() 
en XMLTravelgate.Aggregators.Providers.Hotel.GEN2.GEN2Provider.<configurationAsync>d__34.MoveNext()]StackTrace:[ en System.Xml.Serialization.XmlSerializer.Deserialize(XmlReader xmlReader, String encodingStyle, XmlDeserializationEvents events) 
en System.Xml.Serialization.XmlSerializer.Deserialize(XmlReader xmlReader) 
en Serializers.Xml.DynamicXmlSerializer.UnserializeFromXmlStr(String xml, Type type, XmlReaderSettings xmlReaderSettings, String language) 
en Util.UtilGEN2.<SendRequestAsync>d__14`1.MoveNext() 
--- Fin del seguimiento de la pila de la ubicación anterior donde se produjo la excepción --- 
en System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() 
en System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) 
en System.Runtime.CompilerServices.TaskAwaiter`1.GetResult() 
en XMLTravelgate.Aggregators.Providers.Hotel.GEN2.Manager.GenericAsync`2.<ProcessAsync>d__0.MoveNext() 
--- Fin del seguimiento de la pila de la ubicación anterior donde se produjo la excepción --- 
en System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() 
en System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) 
en System.Runtime.CompilerServices.TaskAwaiter`1.GetResult() 
en XMLTravelgate.Aggregators.Providers.Hotel.GEN2.GEN2Provider.<configurationAsync>d__34.MoveNext()]Message:[Error en el documento XML (1, 444).]InnerException.toString:[System.InvalidOperationException: Error de validación de instancia: 'String' no es un valor válido para eTypeMetaData. 
en Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationReaderConfigurationRS.Read9_eTypeMetaData(String s) 
en Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationReaderConfigurationRS.Read14_ParametersExtendedBase(Boolean isNullable, Boolean checkType) 
en Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationReaderConfigurationRS.Read15_ParametersExtended(Boolean isNullable, Boolean checkType) 
en Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationReaderConfigurationRS.Read16_ConfigurationRS(Boolean isNullable, Boolean checkType) 
en Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationReaderConfigurationRS.Read17_ConfigurationRS()]</description> 
<httpStatusCode>0</httpStatusCode> 
</applicationErrors> 
</ConfigurationRS> 

Any leads you can provide to us would be helpful.