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2 answers
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Hi Guys, I have recently downloaded Fiddler. The program itself is great but whenever I close it and I start epic games then there is always a mistake that is not Internet connection. But as soon as I reopen Fiddler, epic games has a connection. Maybe you know what I have to do so that I can start epic games again without fiddler? Thanks in advance
ivory
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Iron
Iron
 answered on 27 Mar 2026
5 answers
2.1K+ views
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ivory
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Iron
Iron
 answered on 26 Mar 2026
4 answers
1.3K+ views

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 ?

Hardy
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Iron
 answered on 11 Feb 2026
1 answer
19 views

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

  [cause]: Error: unable to verify the first certificate
      at TLSSocket.onConnectSecure (node:_tls_wrap:1674:34)
      at TLSSocket.emit (node:events:519:28)
      at TLSSocket._finishInit (node:_tls_wrap:1085:8)
      at ssl.onhandshakedone (node:_tls_wrap:871:12)
      at TLSWrap.callbackTrampoline (node:internal/async_hooks:130:17) {
    code: 'UNABLE_TO_VERIFY_LEAF_SIGNATURE'
Nick Iliev
Telerik team
 answered on 06 Feb 2026
1 answer
28 views

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!

Nick Iliev
Telerik team
 answered on 19 Jan 2026
1 answer
458 views

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

 

 

ivory
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Iron
Iron
 updated answer on 12 Jan 2026
2 answers
1.9K+ views
Hello so as you have seen my subject question is there a way that i could for example in league of legends add myself blue essensce and things like that?
ivory
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Iron
Iron
 updated answer on 12 Jan 2026
2 answers
408 views
I am trying to capture the traffic while launching Bloons TD 1 but it doesn't appear on fiddler
ivory
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Iron
Iron
 updated answer on 12 Jan 2026
4 answers
347 views
I have a simple problem and hopefully it has a simple solution. I want to limit the speed for an online game, namely Roblox. I edited the line under if (m_SimulateModem), which works great for webpages, but it didn't slow down the game. Is it possible to limit the speed for online games using Fiddler? I believe Roblox uses UDP for communication, so can I edit something to slow UDP communications?
ivory
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Iron
Iron
 updated answer on 12 Jan 2026
1 answer
89 views

I have a C# rule script in fiddler classic, which convert the http request form-data body from "key1=value1" to json {"key1": "value1"}

I am trying to migrate to fiddler everywhere, but I have no idea how to achieve this in fiddler everywhere, where's rule script in fiddler everywhere?

Nick Iliev
Telerik team
 answered on 26 Dec 2025
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