Error in sending post request in release mode C#

I used Microsoft.aspNet.WebApi.Client to send request to server in my project (output is dll). In debug mode all methods (Get, Post) work well. But if i run client in release mode I've got response 500 inteal error.!! Here is code:

 HttpResponseMessage response = client.PostAsJsonAsync("api/calls", Tuple.Create(obj1,
                ob2, obj3, obj4 , obj5)).Result;

How can I know the diffrent between packages or some configuration cause this?