Postman POST request never hits controller endpoint!

[khteh]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

I run a debug session of the application and send a POST request from Postman. The POST request from Postman seems like taking forever and never hit the controller endpoint breakpoint. Irconically, once I cancel the request on the Postman side, it hits the contoller POST method/endpoint and the request completes successfully without seeing anything unusual at the Debug Console. Of course, the Postman won't show any response since the request was already cancelled.

Program.cs:

builder.Services.AddControllersWithViews();
app.MapControllers();

Controller:

[Route("api/[controller]")]
[ApiController]
public class AccountsController : ControllerBase 
{ 
    // POST api/auth/login
    [HttpPost("login")]
    [AllowAnonymous]
    //[ValidateAntiForgeryToken]
    public async Task<ActionResult> Login([FromBody] Models.Request.LogInRequest request)
    {
        if (!ModelState.IsValid) { return BadRequest(ModelState); }
        LogInResponse response = await _mediator.Send(new LogInCommand(request.UserName, request.Password, Request.HttpContext.Connection.RemoteIpAddress?.ToString()));
        return _mapper.Map<JsonContentResult>(response);
    }
}

Expected Behavior

Postman POST request hits controller endpoint.

Steps To Reproduce

No response

Exceptions (if any)

[06/06/2025 10:57:19 +08:00] Debug { Id: 1, Name: "AuthenticationFailed" } IP: CorrelationId: Agent: ContentType: ContentLength: RequestBody: RequestQuery: MemoryUsage:/398065664 Failed to authenticate HTTPS connection. {SourceContext="Microsoft.AspNetCore.Server.Kestrel.Https.Internal.HttpsConnectionMiddleware", ConnectionId="0HND4KKA9F3V6", ThreadId=18, ExceptionDetail={["Type"]="System.IO.IOException", ["HResult"]=-2146232800, ["Message"]="Received an unexpected EOF or 0 bytes from the transport stream.", ["Source"]="System.Net.Security", ["TargetSite"]="Void MoveNext()"}} 
System.IO.IOException: Received an unexpected EOF or 0 bytes from the transport stream.
   at System.Net.Security.SslStream.ReceiveHandshakeFrameAsync[TIOAdapter](CancellationToken cancellationToken)
   at System.Net.Security.SslStream.ForceAuthenticationAsync[TIOAdapter](Boolean receiveFirst, Byte[] reAuthenticationData, CancellationToken cancellationToken)
   at Microsoft.AspNetCore.Server.Kestrel.Https.Internal.HttpsConnectionMiddleware.OnConnectionAsync(ConnectionContext context)

[06/06/2025 10:57:19 +08:00] Debug { Id: 2, Name: "ConnectionStop" } IP: CorrelationId: Agent: ContentType: ContentLength: RequestBody: RequestQuery: MemoryUsage:/398065664 Connection id ""0HND4KKA9F3V6"" stopped. {SourceContext="Microsoft.AspNetCore.Server.Kestrel.Connections", ThreadId=18} 

[06/06/2025 10:57:19 +08:00] Debug { Id: 7, Name: "ConnectionWriteFin" } IP: CorrelationId: Agent: ContentType: ContentLength: RequestBody: RequestQuery: MemoryUsage:/398065664 Connection id ""0HND4KKA9F3V6"" sending FIN because: ""The Socket transport's send loop completed gracefully."" {SourceContext="Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets", ThreadId=18} 

[06/06/2025 10:57:19 +08:00] Debug { Id: 3, Name: "HttpsConnectionEstablished" } IP: CorrelationId: Agent: ContentType: ContentLength: RequestBody: RequestQuery: MemoryUsage:/398065664 Connection "0HND4KKA9F3V7" established using the following protocol: "Tls13" {SourceContext="Microsoft.AspNetCore.Server.Kestrel.Https.Internal.HttpsConnectionMiddleware", ThreadId=8} 

Exception thrown: 'System.InvalidOperationException' in Microsoft.AspNetCore.Server.Kestrel.Core.dll
4
Exception thrown: 'System.InvalidOperationException' in System.Private.CoreLib.dll

.NET Version

9.0.106

Anything else?

#61844

[khteh]

FYI, the application web UI and swagger UI work perfectly.

[DeagleGross]

There is no info about how client sends the request. Stack trace clearly states that exception happened during TLS Handshake establishment, so maybe you can check how you have setup httpS on your side?

And for investigation purposes, please provide a repro - you can create a github repo and put only relevant/minimal code to the issue so that we can debug it and understand the root cause.

Thanks!

[khteh]

https://github.com/khteh/AspNetCoreWebApi

I run the app locally, both Windows 11 VS2022 and Ubuntu 25.04 VSCode.
This has been working all the time since the project's inception until upgraded to .Net 9.

[halter73]

System.IO.IOException: Received an unexpected EOF or 0 bytes from the transport stream.
  at System.Net.Security.SslStream.ReceiveHandshakeFrameAsync[TIOAdapter](CancellationToken cancellationToken)
  at System.Net.Security.SslStream.ForceAuthenticationAsync[TIOAdapter](Boolean receiveFirst, Byte[] reAuthenticationData, CancellationToken cancellationToken)
  at Microsoft.AspNetCore.Server.Kestrel.Https.Internal.HttpsConnectionMiddleware.OnConnectionAsync(ConnectionContext context)

This indicates an issue during the TLS handshake. Usually this means the client rejected the certificate. Do you see this issue on non-HTTP endpoints? If not, does running dotnet dev-certs https --trust help?

• https://learn.microsoft.com/dotnet/core/tools/dotnet-dev-certs
• https://learn.microsoft.com/aspnet/core/security/enforcing-ssl?view=aspnetcore-9.0#trust-the-aspnet-core-https-development-certificate

Or maybe you should reconfigure your application to use the development certificate for local testing, since it appears to be overridden here.

Another option might be to manually add your custom cert as a CA in Postman or simply turning SSL certificate validation off.

https://learning.postman.com/docs/sending-requests/authorization/certificates/#troubleshoot-certificate-errors

If none of these solutions work for you, we will need a simpler repro that doesn't require irrelevant steps like configuring a
PostgreSQL server.

[khteh]

turning SSL certificate validation off.

To no avail. Same behaviour. Nothing changes.