Item has already been added. Key in dictionary: 'Int32 Count[Object](System.Collections.Generic.IEnumerable`1[System.Object])' Key being added: 'Int32...

Server Error in '/Admin' Application.

Item has already been added. Key in dictionary: 'Int32 Count[Object](System.Collections.Generic.IEnumerable`1[System.Object])'  Key being added: 'Int32 Count[Object](System.Collections.Generic.IEnumerable`1[System.Object])'

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

Exception Details: System.ArgumentException: Item has already been added. Key in dictionary: 'Int32 Count[Object](System.Collections.Generic.IEnumerable`1[System.Object])'  Key being added: 'Int32 Count[Object](System.Collections.Generic.IEnumerable`1[System.Object])'

Source Error: 


Line 856:        IDCCircleDataContext idc = new IDCCircleDataContext();
Line 857:
Line 858:        var qCampaignFilters = idc.Filters.OrderBy(c => c.FilterName);
Line 859:
Line 860:        ddlLoadFilter.Items.Clear();

Source File: d:\IDCC\Website\IDCCircle\Admin\Campaigns\Event\NewSendMailToUsers.aspx.cs    Line: 858 

Stack Trace: 


[ArgumentException: Item has already been added. Key in dictionary: 'Int32 Count[Object](System.Collections.Generic.IEnumerable`1[System.Object])'  Key being added: 'Int32 Count[Object](System.Collections.Generic.IEnumerable`1[System.Object])']
   System.Reflection.CerHashtable`2.Insert(K[] keys, V[] values, Int32& count, K key, V value) +7473762
   System.Reflection.CerHashtable`2.Preallocate(Int32 count) +301
   System.RuntimeTypeCache.GetGenericMethodInfo(RuntimeMethodHandle genericMethod) +240
   System.RuntimeType.GetMethodBase(RuntimeTypeHandle reflectedTypeHandle, RuntimeMethodHandle methodHandle) +438
   System.Reflection.RuntimeMethodInfo.MakeGenericMethod(Type[] methodInstantiation) +320
   System.Linq.Queryable.OrderBy(IQueryable`1 source, Expression`1 keySelector) +213
   Campaigns_Generic_NewSendMailToUsers.BindDDL() in d:\IDCC\Website\IDCCircle\Admin\Campaigns\Event\NewSendMailToUsers.aspx.cs:858
   Campaigns_Generic_NewSendMailToUsers.Page_Load(Object sender, EventArgs e) in d:\IDCC\Website\IDCCircle\Admin\Campaigns\Event\NewSendMailToUsers.aspx.cs:49
   System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +14
   System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +35
   System.Web.UI.Control.OnLoad(EventArgs e) +99
   System.Web.UI.Control.LoadRecursive() +50
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +627

Version Information: Microsoft .NET Framework Version:2.0.50727.5456; ASP.NET Version:2.0.50727.5456