How to resolve WCF datacontracts problem

Hi All ,

I have two data contracts of same contents in two different  namespaces. i have copied one datacontract to another and

passed to a particular method. but it is giving the below error and throwing exception. it is not going into that method.

Please let me know any ideas /suggestions on how to resolve this.
Appreciate your help:

Exception errror:

{"Type 'System.Collections.Generic.List`1[[GlobalWcfServiceLib.TopicDetailsInfo, GlobalWcfContracts, Version=1.2.2.0, Culture=neutral,

 PublicKeyToken=17c64733a9775004]]' with data contract name 'ArrayOfTopicDetailsInfo:http://CName.GlobalService/11.1/2010/11'
 is not expected. Consider using a DataContractResolver or add any types not known statically to the list of
  known types - for example, by using the KnownTypeAttribute attribute or by
adding them to the list of known types passed to DataContractSerializer."}

Here is my scenario : i am copying the data from dc to new data contract as below. after copying , when i am executing the createsubscriptions method i am getting the above mentioned error. i have given the details of data contract and error in the original question. please refer to that as well.
Method1(SubscriptionDataContracts dc)
{
SubscriptionDataContract subscriptionDataContract = new SubscriptionDataContract();

              List<SubscriptionTopicInfo> topicsInfo = dc.TopicList;
              List<SubscriptionTopic> newTopicsList = new List<SubscriptionTopic>();
              subscriptionDataContract.ExtensionData = dc.ExtensionData;

              subscriptionDataContract.UserID = dc.UserID;

                for (int i = 0; i < topicsInfo.Count; i++)
                {
                    SubscriptionTopic topic = new SubscriptionTopic();
                    topic.DBHandle = topicsInfo[i].DBHandle;
                    topic.Topic = topicsInfo[i].Topic;
                    topic.Target = topicsInfo[i].Target;
                    newTopicsList.Add(topic);
                }
                subscriptionDataContract.TopicList = newTopicsList;

                CreateSubscriptions(subscriptionDataContract);   //getting teh above mentioned error here
  }

Hi ,

I have data contract as follows. It has knownType attribute to most of them. but still i am getting the above mentioned error while passing this data contract to another method. Please let me know where exactly i need to add the knowntype attribute. I am really in confusion in finding out where exaclty is the problem ?

Appreciate your help.

 [DataContract(Name = "TopicDetailsInfo", Namespace = "http://CName.GlobalService")]
    [Serializable]
    public class TopicDetailsInfo
    {        
        protected object topic;        
        protected object baseObjectType;       
        [DataMember]
        public object BaseObjectType
        {
            get
            {
                return baseObjectType;
            }
            set
            {
                baseObjectType = value;
            }
        }

        [DataMember]
        public object TopicID
        {
            get
            {
                return topic;
            }
            set
            {
                topic = value;
            }
        }

        static public TopicDetailsInfo CreateTopic<T, mT>(IComparable<T> objectType, IComparable<mT> objectID)
        {
            var topicDetails = new TopicDetailsInfo();
            topicDetails.BaseObjectType = objectType;
            topicDetails.TopicID = objectID;
            return topicDetails;

        }

    }


    [DataContract(Name = "SubscriptionTopicInfo", Namespace = "http://CName.GlobalService")]
    [KnownType(typeof(List<TopicDetailsInfo>))]
     [Serializable]
    public class SubscriptionTopicInfo
    {
        private object topic;
        private object target;
        private object creator;
        [DataMember]
        public object Topic
        {
            get
            {
                return topic;
            }
            set
            {
                topic = value;
            }
        }
        [DataMember]
        public object Target
        {
            get
            {
                return target;
            }
            set
            {
                target = value;
            }
        }

        [DataMember]
        public object DBHandle
        {
            get
            {
                return creator;
            }
            set
            {
                creator = value;
            }
        }
        static public SubscriptionTopicInfo CreateSubscriptions<T, mT, nT>(IList<TopicDetailsInfo> topic, IComparable<mT> target, IComparable<nT> handle)
        {

            var subscriptionTopic = new SubscriptionTopicInfo();

            subscriptionTopic.Target = target;
            subscriptionTopic.Topic = topic;
            subscriptionTopic.DBHandle = handle;

            return subscriptionTopic;
        }

    }


    [DataContract(Name = "SubscriptionData", Namespace = "http://CName.GlobalService")]
    [KnownType(typeof(List<SubscriptionTopicInfo>))]
    [Serializable]
    public class SubscriptionDataContracts : IExtensibleDataObject
    {
        private ExtensionDataObject extensionDataObjectValue;       
        [DataMember]         
        public string UserID 
        {
            get;
            set;

        }
       
        [DataMember]
        public string ProjectID 
        {
            get;
            set;

        }
        [DataMember]
        public string FromDiscipline 
        {
            get;
            set;

        }
        
        [DataMember]
        public string ModuleID 
        {
            get;
            set;

        }
        
        [DataMember]
        public string SessionID
        {
            get;
            set;

        }
        
        [DataMember]
        public List<SubscriptionTopicInfo> TopicList
        {
            get;
            set;
        }        
        public ExtensionDataObject ExtensionData
        {
            get
            {
                return extensionDataObjectValue;
            }
            set
            {
                extensionDataObjectValue = value;
            }
        }

}