Last Updated: 13 Jan 2023 09:20 by ADMIN


We've been using FiddlerCore 5.0.0 for a while, but recently found that we can't open any SAZ files we generate. When we try to open any in Fiddler Classic we get a popup with the message: The selected file is not a Fiddler-generated .SAZ archive of Web Sessions.

Here are the things I've tried:

  • When renaming the saz to zip the contents look correct.
  • After using the repair option when opening the saz in FiddlerClassic the saz then opens.
  • Renaming the repaired saz to zip and comparing the contents the the original saz as zip - contents compare identical.
  • We use a custom saz writer that hasn't been changed since we originally integrated FiddlerCore, but I'm seeing the same error in each Session object we cache for list passed to Utilities.WriteSessionArchive : "Session #error CS0103: The name 'm_requestID' does not exist in the current context, error CS0103: The name 'm_state' does not exist in the current context". This is not coming from our code. 
  • I tried not using a custom writer, but just call Utilities.WriteSessionArchive, the call fails but I can't determine the reason why.
  • Attached is a sample saz file we generate that causes the issues described.

Thanks for any assistance.

Last Updated: 21 Oct 2021 05:23 by ADMIN
Created by: zd
Comments: 0
Type: Feature Request
Last Updated: 01 Dec 2020 14:30 by ADMIN
Created by: Sven
Comments: 2
Type: Feature Request

Hello Telerik Team,

Could you please let me know with which version of Fiddler core library HTTP/2 will be supported.

Many thanks, Sven

Won't Fix
Last Updated: 01 Dec 2020 12:48 by ADMIN
Created by: Sven
Comments: 1
Type: Feature Request


Could you please let me know why the Fiddler core library is not supporting HTTP/2 yet. It is standard since a while and it shouldn't be a hard deal to get it implemented. If you want to be state of the art you should invest here.

Many thanks, Sven

Need More Info
Last Updated: 09 Jun 2020 15:37 by ADMIN
Created by: Albert
Comments: 1
Type: Feature Request


I would like to be able  to export a WebTest directly from FiddlerCore using oSession.

Thank you.


Albert Zakhia

Last Updated: 14 Nov 2019 15:11 by ADMIN
Release FiddlerCore 5.0.0
Created by: Calvin
Comments: 0
Type: Feature Request
I want to use PAC file., this way, if my proxy accidently quits without remove the proxy setting, the browser will be able to continue to work since it can't find the pac file, thus consider it "No proxy".


But When I set the flags, if I don't include: "RegisterAsSystemProxy", the PAC file will not registered.

If I DO include "RegisterAsSystemProxy", the PAC file is registered, but also the proxy servers, 8888 for http and https. What's the point to have both registered, and it negate my purpose.

Anyway to hook up PAC file only?


Also, how to  modify the PAC file content, for GOD's sake?