.NET httpclient 406 not acceptable-CodePudding

I am trying to make a http get call using .NET and I am getting 406 Not accepted error. The same request when I try to do from PostMan its working fine! I have tried verifying my headers and also mapped it with the same postman request (including the postman's hidden auto-generated headers. Tried with different accept headers also. Nothing worked, can someone point me in some direction how I can identify the issue. Unfortunately I dont have any control over the server endpoint.

My .NET console app code is this!

            HttpClient httpClient = new HttpClient();
            httpClient.BaseAddress = new Uri(BaseURL   "reports/1.0/");
            httpClient.DefaultRequestHeaders.Add("consumerKey", ConsumerKey);
            httpClient.DefaultRequestHeaders.Add("Authorization", "Bearer "   AccessToken);
            httpClient.DefaultRequestHeaders.TryAddWithoutValidation("sessionToken ", ott);
            httpClient.DefaultRequestHeaders.Add("User-Agent", "PostmanRuntime/7.29.0");
            httpClient.DefaultRequestHeaders.Add("Accept-Encoding", "gzip, deflate, br");
            httpClient.DefaultRequestHeaders.Add("Connection", "keep-alive");
            httpClient.DefaultRequestHeaders.Add("Accept", "*/*");

            var response = await httpClient.GetAsync("orders");
            response.EnsureSuccessStatusCode();

Request from postman console looks like this.

Same request from Postman's raw log

GET /apim/reports/1.0/orders HTTP/1.1
consumerKey: L3UnAkofqNfW0rhgtYUz7UQzN58a
sessionToken: DA05DA9F178D8C0E5754F03E617A49546330776ABFDDBC
Accept: application/xml
Authorization: Bearer 6971ce62-789e-3b1b-b805-82560f1f21c6
Postman-Token: 04df336c-9226-4eab-8054-c004940e4660

HTTP/1.1 200 OK
Strict-Transport-Security: max-age=15768000; includeSubDomains
Access-Control-Expose-Headers:
Access-Control-Allow-Origin: *
Access-Control-Allow-Methods: GET
Timestamp: 46
Access-Control-Allow-Headers: authorization,Access-Control-Allow-Origin,Content-    Type,SOAPAction,consumerKey,sessionToken,Authorization
Content-Type: application/json
Date: Sun, 22 May 2022 10:57:28 GMT
Transfer-Encoding: chunked

The failing request from Visual Studio seems like having 200 in the fiddler! Below is the response of failing request captured in fiddler.

HTTP/1.1 200 Connection Established
FiddlerGateway: Direct
StartTime: 18:13:22.888
Connection: close

This is a CONNECT tunnel, through which encrypted HTTPS traffic flows.
To view the encrypted sessions inside this tunnel, enable the Tools > Options > HTTPS > Decrypt HTTPS traffic option.

A SSLv3-compatible ServerHello handshake was found. Fiddler extracted the parameters below.

Here is the Visual Studio error I receive.

Any suggestions on what can be the issue or how I can troubleshoot will be of great help! Please advise.

CodePudding user response：

It seems like there is a space in the headerName sessionToken thats causing this weird issue. Removing the space resolved the issue.

CodePudding user response：

I faced the same issue in one project. It was due to two apis with same name and I haven't mentioned the request method. That's why server wasn't able to map the request to any of them try to look for the request method.