Cognitive service is not serializable

[subhamawasthi]

Hello Team,

I was consuming the face in a sample Bot project.
I was able to exploit the API but after the completion of process i,e face Analysis I am getting a Error "Sorry my bot have Issue." on checking with emulator for POST.500 Error it has the following description:
An error has occurred.",\r\n "exceptionMessage": "Type 'Microsoft.Azure.CognitiveServices.Vision.Face.Models.DetectedFace' in Assembly 'Microsoft.Azure.CognitiveServices.Vision.Face, Version=0.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35' is not marked as serializable.",\r\n "exceptionType": "System.Runtime.Serialization.SerializationException",\r\n

Please help me with the way around for this error.

Regards