Azure Face Detect API - An Error occurred while sending the request

Question

I am using Azure Cognitive Services to detect faces in an image in my ASP.NET MVC web application. But its "DetectWithStreamAsync" always throws "An error occurred while sending the request". I took a reference from this project https://github.com/Azure-Samples/Cognitive-Face-CSharp-sample which is WPF app. However, this WPF app does not throw the same exception when I use the same code, subscription key and endpoint URL. The exceptions are thrown only when requests are made from by MVC application.

Edit: I have also tried using Microsoft.ProjectOxford.Face's, "DetectAsync" method, but got the same exception.

My Code is as follows:

using Microsoft.Azure.CognitiveServices.Vision.Face;
using Microsoft.Azure.CognitiveServices.Vision.Face.Models;

namespace MyApplication.FaceRecognition
{
    public class FaceRecognitionService
    {
        private static string key =ConfigurationManager.AppSettings["FaceAPIKey"];
        private static string endPoint =ConfigurationManager.AppSettings["FaceAPIEndPoint"];  

        private readonly IFaceClient faceClient = new FaceClient(
          new ApiKeyServiceClientCredentials(key),
          new System.Net.Http.DelegatingHandler[] { });


        public FaceRecognitionService()
        {  
            faceClient.Endpoint = endPoint;
        }

        public async Task<Guid> DetectFace(string imgPath)
        {
            Guid faceID = Guid.Empty;

            try
            {
                using (Stream faceimagestream = File.OpenRead(imgPath))
                {
                    var faces = await faceClient.Face.DetectWithStreamAsync(faceimagestream,true,false);
                    if (faces.Count > 0)
                        faceID = faces[0].FaceId?? default;
                }

                return faceID;
            }
            catch (Exception ex)
            {

                throw ex;
            }
        }
        
    }
    
}

Answer 1

Upon inspection of inner exception, I got "The underlying connection was closed, an unexpected error occured on a send". It was due to issue with security protocol.Turns out my httpRuntime targetFrameworkwas 4.5, changing it to 4.7 or enabling TLS 1.2 resolved the above error.