I installed Fiddler last Dec. and runs well in couple of days.But few days ago,Fiddler stop capturing any kind of request and block all the request.Recently,I installed a  printer driver of HP which I think might be the reason.Although I uninstall the driver and every software came with it,Fiddler still not working.BTW,Fiddler works well in save-mode with or without the printer dirver installed.Hope u can solve this for me.Thx.

The HP printer Driver package name:HP_Color_LaserJet_Pro_MFP_M176,was downloaded from the HP website.

Welcome to the Fiddler Insiders Forum!

This is a meeting place for the most frequent and active Fiddler users and the developers team behind Fiddler. 

New mainstream functionality as well as prototypes of exotic features that may never make it to production are shared and discussed here in an effort to shape the future of Fiddler. Feel free to bring up any topic of interest. Your insight is most welcome.

Membership here is invitation based. If you would like to add another Fiddler user, please, contact the admins.

 

 

 

Being the very noobie I am with https, how is it that Fiddler can decrypt what is in the headers?  Does that imply that any "man in the middle" could decrypt those?  Is it REQUIRED that I encrypt what is in the Header content?  Or, if it is https, everything is encrypted including the headers?

We have been experimenting with strictly per user installation of Fiddler for some time. Here you will find a stable beta of that flavor. All extensions are also attached since the original ones won't work in this setup.

 

The per user installation cannot coexist with the all users one. So if it finds Fiddler for all users installed it will remove it prior to installing. It leaves no traces on the system after uninstall so switching between per user and all users Fiddler is a matter of simple uninstall/reinstall.

 

---------------------------
Uncaught Exception in Session #20
---------------------------
Fiddler has encountered an unexpected problem. If you believe this is a bug in Fiddler, please copy this message by hitting CTRL+C, and submit a bug report at http://www.telerik.com/forums/fiddler.

Object reference not set to an instance of an object.

Type: System.NullReferenceException
Source: Fiddler
   at Fiddler.ServerChatter.Ÿ.Ÿ(Object ƒ, EventArgs ‚Ÿ) in c:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\ServerChatter.cs:line 1341

   at Fiddler.Session.set_state(SessionStates value) in c:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\Session.cs:line 745

   at Fiddler.Session.€(Boolean ) in c:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\Session.cs:line 6040

   at Fiddler.Session.‘() in c:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\Session.cs:line 3912

   at Fiddler.ServerChatter.Œ() in c:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\ServerChatter.cs:line 1454

   at Fiddler.Session.‘() in c:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\Session.cs:line 3554

   at Fiddler.Session.(Object ) in c:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\Session.cs:line 3347


Fiddler v4.6.2.32002 (x64 AMD64) [.NET 4.0.30319.34209 on Microsoft Windows NT 6.1.7601 Service Pack 1] 
---------------------------
OK   
---------------------------

Please help!

I've disabled every firewall I could, and did everything a admin commented on a other post but did not work! 

I'm using Chorme and i'm getting pissed, I tried to trust it but it came out with the error. 

If you can please help me.

Thanks - Kyoto

Hi,

Recently, when running Fiddler, my browser is slow to complete requests on certain servers; averaging 20-40 seconds per request.

Chrome shows "Waiting for proxy tunnel", and I can see in the Fiddler Statistics, it says: 

TCP/IP Connect: 42039ms

I'm doing local development on Visual Studio, and the local requests are fast, but the CDN's make every page load take about 40 seconds.  And regular browser use typically takes that long too.  Not every site, probably 50%.  

I uninstalled (and wiped setting) and reinstalled which didn't help.  I also turned off "Capture HTTPS CONNECTs" which didn't do anything either.

Any help would be appreciated.  I love the tool and rely on it... but it's unusable for me right now.

Thanks,

Toby

I'm developing some WCF web service calls, and want to test how the download times compare when using a modem connection.

I started Fiddler and checked the Rules -> Performance -> Simulate Modem speeds option. I can see that this works, as if I refresh a web page, it's slower. I tried downloading some files of around 3-6Mb, and again I could see the difference. Normally these would be pretty instant, with the performance option on, they took a few seconds.

I then tried to make my service calls. Without the Fiddler option, they typically take about 300-400ms to download about 1.5Mb. However, with the performance option on, the call takes about 40-60 seconds. This is way to slow to be realistic.

This is all running on my local machine, using Visual Studio 2015.

Anyone any idea why it's so slow?

Hi,

 

I was playing around with fiddler and its scripts while Steam was running.

The first page I saw was my Trade Offer page and I wanted to replace that with my own Website just to mess around.

What I did was: 

 

And I did not what I wanted it to do so I removed it and saved..... Now I have the issue that in the Steam client the page constantly becomes my won website: coddr.net

And I want that to be removed, I tried to do 

 

And it works but when I close down the software its somehow coddr again. How can I fix this?

Hi!

Yesterday i installed Fiddler2 on my PC (stable public version) and at registry saw version 2.5.1.6, but at download page (http://www.telerik.com/download/fiddler) i saw Fiddler version 2.5.1.2!

Now at download page (http://www.telerik.com/download/fiddler) i saw that you build a new version of Fiddler 2.6.0.0

I download it, but version is the same (still Fiddler 2.5.1.6)

The same situation with Fiddler4 

Why do you use two different versions - for public page and for real version of app?That's very uncomfortable!

Most of all, if i installed version of Fiddler 2.5.1.2 and try to update it thru autoupdater, i would have no available updates. But if i installed version later (for example, 2.4.9.9) i would install Fiddler version 2.5.1.6 thru your autoupdater, but on your download page i saw public stable version 2.5.1.2. (that's all i tested yesterday)

 

Please, can you fix it?