Thanks to Prabhjyot's help, I was able to find out the typo in the request body. I had provideType. It should be providerType.

@cadyh ,

Can you please share the request payload as it is being passed using the code and postman to compare the values?

The request using the code is in the question.

Here is the request using Postman

Request Headers

Date: Mon, 12 Jul 2021 13:11:34 GMTContent-Type: application/jsonAuthorization: Signature keyId="xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",algorithm="hmac-sha256",headers="(request-target) host date content-type content-length",signature="8WaJl5RGH88c7zJJ7Ls5/1mexev6K35MurIZnI0sEKo="Content-Length: 171User-Agent: PostmanRuntime/7.28.1Accept: */*Cache-Control: no-cachePostman-Token: 92636f9a-73f8-4d51-b8c0-a0fee5ea9d53Host: api-worldcheck.refinitiv.comAccept-Encoding: gzip, deflate, brConnection: keep-alive

Request Body

{ "entityType": "ORGANISATION", "groupId": "xxxxxxxxxxxxxxxxxxxxxxxxx", "providerTypes": [ "WATCHLIST" ], "name": "Lajnat ul Masa Eidatul Afghaniab" }

@cadyh ,

Thanks for the details.

Can you please confirm if you are using the same format as above of the request payload in the code and postman? Or are the formats getting changed in anyway?

No, the format is not changed. They are both from WorldCheck sample code. The have changedthe name and added this code "ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;" from answer in other question to solve the problem with the error "Could not create secured channel". I have tried with different names.

I noticed there is a space between post and gatewayurl that I removed somehow( must be when I tried different things to solve this problem) in the dataToSign variable. I added back in. This is now the same as the sample code (below)

UTF8Encoding encoding = new UTF8Encoding();

byte[] byte1 = encoding.GetBytes(postData);

string msg = postData;

string dataToSign = "(request-target): post " + gatewayurl + "cases\n" +

"host: " + gatewayhost + "\n" + // no https only the host name

"date: " + date + "\n" + // GMT date as a string

"content-type: " + "application/json" + "\n" +

"content-length: " + byte1.Length + "\n" +

msg;

I now get a different error. With the space back in I now get error 500 Internal Server Error.

This is the dataToSign value: "(request-target): post /v2/cases\nhost: api-worldcheck.refinitiv.com\ndate: Tue, 13 Jul 2021 20:54:17 GMT\ncontent-type: application/json\ncontent-length: 138\n{\"entityType\":\"ORGANISATION\",\"groupId\":\"xxxxxxxxxxxxxxxxxxxxxxx\",\"provideTypes\":[\"WATCHLIST\"],\"name\":\"Lajnat ul Masa Eidatul Afghaniab\"}"

I see the postman body has new line and indented so I removed them all. The content length from postman is now show 139, it is 1 longer than the content length from C# code. I can't find where that 1 different in length is. Is it really the cause of the issue?

Request HeadersDate: Tue, 13 Jul 2021 20:51:43 GMTContent-Type: application/jsonAuthorization: Signature keyId="xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",algorithm="hmac-sha256",headers="(request-target) host date content-type content-length",signature="e/Sxhitb/KbbSdt3Qqml0KsPbIGMLR0XwzWT6eCm5Cs="Content-Length: 139User-Agent: PostmanRuntime/7.28.1Accept: */*Cache-Control: no-cachePostman-Token: 4a30df6a-6450-400c-afa7-65210b4a92eaHost: api-worldcheck.refinitiv.comAccept-Encoding: gzip, deflate, brConnection: keep-alive

@cadyh ,

I will send you an email, so we can get on a call to look further into the issue.