Event ID 3 WebHost failed to process a request.

Hello All

I am getting cont. error on my server below -

System.ServiceModel 4.0.0.0

WebHost failed to process a request.  
Sender Information: System.ServiceModel.Activation.HostedHttpRequestAsyncResult/51694289  Exception: System.ArgumentException: An item with the same key has already been added.    at System.Runtime.AsyncResult.End[TAsyncResult](IAsyncResult result)   at System.ServiceModel.Activation.HostedHttpRequestAsyncResult.End(IAsyncResult result)  Process Name: w3wp  Process ID: 4456

Please advise-

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Thanks Ranveer Katiyar