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Could not establish trust relationship for the SSL/TLS secure channel

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Hi everyone,

I am trying to call an external web API in d365fo x++ but I am getting an error when I pass the server url and header parameters. The error message is /The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel./ I am wondering if anyone has encountered this error before and knows how to fix it.

Here is my code for calling the external API:

System.Net.HttpWebRequest request;
System.IO.Stream stream;
System.Exception sysEx;

System.Net.ServicePointManager::SecurityProtocol=System.Net.SecurityProtocolType::Tls12;

request = System.Net.WebRequest::Create(/url/) as System.Net.HttpWebRequest;
request.Method = 'POST';
request.ContentType = 'application/json';
// Set the request headers
System.Net.WebHeaderCollection headerCollection = request.Headers;
headerCollection.Set('Authorization', 'Bearer XXXXXXXXXXXXX');
var utf8 = System.Text.Encoding::get_UTF8();

// Set the request body
var byteArrayPayload = utf8.GetBytes(/string value/);

try
{
// send out the payload
using (System.IO.Stream dataStream = request.GetRequestStream())
{
dataStream.Write(byteArrayPayload, 0, byteArrayPayload.Length);
}

using (System.Net.HttpWebResponse response = request.GetResponse() as System.Net.HttpWebResponse)
{

stream = response.GetResponseStream();
System.IO.StreamReader reader = new System.IO.StreamReader(stream);
str responseBody = reader.ReadToEnd();
}
}
catch (sysEx)
{
throw;
}

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Layan Jwei 8,165 Super User 2026 Season 1 on at

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Hi User,

Did you try to call this URL from postman and it worked?

To double check if it's an issue from the code or not, then please try to call a public API url in your x++ code
Choose one of the public APIs here and let us know (https://documenter.getpostman.com/view/8854915/Szf7znEe)

Thanks,
Layan Jweihan

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Community member 2 on at

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Hi Layan Jwei,

I have tried the API using Postman and it works fine. I have also tested it in a C# console application and it works as expected. However, when I use the API in X++, I get this error. Do you have any idea what could be causing this problem? Thank you for your help.

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Layan Jwei 8,165 Super User 2026 Season 1 on at

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Hi User,

Did you try to call the public api i gave you in the previous reply using x++? if it works, then the issue is not from your code and might be related to firewall or security. However, if it doesn't work as well, then there might be sth with the code. so please confirm

Thanks,
Layan Jweihan

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