Hey everyone,

I’m hitting a bit of a wall with mTLS in Fiddler Everywhere. My logs are showing the following error repeatedly: "[Error] [Fiddler] The server [domain] requested a client certificate, but no client certificate was available."

The Situation:

• I have my client certificate ready (as a .pfx, no password).

• My setup involves several subdomains, specifically:

  • appdata.mydomain.com

  • apps-boost-global.mydomain.com

• They all use the SAME certificate.

The Problem: I can’t find a clear, definitive path on where to save these files so Fiddler Everywhere actually "sees" and picks them up. I've seen mentions of Documents\FiddlerCore, .fiddler\ClientCerts, and others, but none seem to trigger the handshake correctly.

My Questions:

1. What is the exact directory path Fiddler Everywhere uses for client certificates in the latest version?

2. Since I’m using the same cert for multiple domains, do I need to duplicate and rename the file for every single subdomain (e.g., hostname.pfx), or is there a way to map one cert to multiple hosts in the UI/Settings?

3. Does the file extension matter (should I use .pfx, .p12, or rename to .cer)?

   
   

Hi, i get this error on any site any browser, 

when i looked at the certificate list, i see that the certificate is expired:

i just reinstalled the last version, but the problem persists

is there any way to fix that ?

I need Fiddler to capture my call from nodejs. 

I call https://domain from nodejs like this

  import { ProxyAgent, fetch } from 'undici';
  const dispatcher = new ProxyAgent('http://127.0.0.1:8888' )
   var r2 = await fetch('https://domain', {
	method: 'POST',
	dispatcher,
	headers: {	
                 ...}
	  },
    body:  ...
  }
  );
  var r2data = await r2.json();

I can do the above call to http://domain, but when I changed to https://domain, I got the below error, any idea how do I handle this? thanks

Hello,

In my application using FiddlerCore, I see that Windows Search Box on Windows 11 isn't able to make connections to the internet. I would like to be able to get this to work in some way but I'm not sure how.

I did some investigation by trying out Fiddler Everywhere and found that the same problems occurs most of the time, except sometimes when the root certificate is installed to machine store. I tried installing the certificate to machine store for my FiddlerCore application but it still didn't remedy the issue. 

Please let me know if there's any solution!

Hello

I am currently trying to track any traffic of the game client, but for whatever reason it does not seem to pick up any of it.
All I have found so far was another Thread on this Forum which could not provide the details I need to get the information that I require.

According to the thread the client does not use the windows default proxy.. so what can I do in order to track the traffic?

Any help is appreciated.

~ Dinh