datacontractserializer - How to resolve an error with WCF data contract -Message = "There was an error while trying to serialize parameter -

i have 2 data contracts of same contents in 2 different namespaces. have copied 1 datacontract and

passed particular method. giving below error , throwing exception. not going method.

please let me know ideas /suggestions on how resolve this.appreciate help:

exception errror: {"type 'system.collections.generic.list`1[[globalwcfservicelib.topicdetailsinfo, globalwcfcontracts, version=1.2.2.0, culture=neutral, publickeytoken=17c64733a9775004]]' data contract name 'arrayoftopicdetailsinfo:http://cname.globalservice/11.1/2010/11' not expected. consider using datacontractresolver or add types not known statically list of known types - example, using knowntypeattribute attribute or adding them list of known types passed datacontractserializer."}

message = "there error while trying serialize parameter http://cname.sharedservices.dbservicelib:subscriptiondatacontract. innerexception message 'type 'system.collections.generic.list`1 [[globalwcfservicelib.topicdetailsinfo, globalwcfcontra...

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here scenario : copying data dc new data contract below. after copying , when executing createsubscriptions method getting above mentioned error. have given details of data contract , error attached question. please refer 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;                  (int = 0; < 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 above mentioned error in dll after going method     } 

//////////////////////////////// //my data contract

 [datacontract(name = "topicdetailsinfo", namespace = "http://cname.globalservice")]     [serializable]     public class topicdetailsinfo     {                 protected object topic;                 protected object baseobjecttype;                [datamember]         public object baseobjecttype         {                         {                 return baseobjecttype;             }             set             {                 baseobjecttype = value;             }         }          [datamember]         public object topicid         {                         {                 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         {                         {                 return topic;             }             set             {                 topic = value;             }         }         [datamember]         public object target         {                         {                 return target;             }             set             {                 target = value;             }         }          [datamember]         public object dbhandle         {                         {                 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         {                         {                 return extensiondataobjectvalue;             }             set             {                 extensiondataobjectvalue = value;             }         }  }