For a few months now on my Windows 10 machine I can't start Fiddler successfully.

Here's what I get in the Event logs:

Log Name:      Application
Source:        Application Error
Date:          30.01.2018 11:05:37
Event ID:      1000
Task Category: (100)
Level:         Error
Keywords:      Classic
User:          N/A
Computer:      ****
Description:
Faulting application name: Fiddler.exe, version: 4.6.3.50306, time stamp: 0x584b0128
Faulting module name: KERNELBASE.dll, version: 10.0.16299.15, time stamp: 0x4736733c
Exception code: 0xe0434352
Fault offset: 0x0000000000013fb8
Faulting process id: 0x10b98
Faulting application start time: 0x01d399a11c497360
Faulting application path: C:\Program Files (x86)\Fiddler2\Fiddler.exe
Faulting module path: C:\WINDOWS\System32\KERNELBASE.dll
Report Id: 021dcf44-7589-4944-a00d-8f3eb1243ed8
Faulting package full name: 
Faulting package-relative application ID: 
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
  <System>
    <Provider Name="Application Error" />
    <EventID Qualifiers="0">1000</EventID>
    <Level>2</Level>
    <Task>100</Task>
    <Keywords>0x80000000000000</Keywords>
    <TimeCreated SystemTime="2018-01-30T08:05:37.110892600Z" />
    <EventRecordID>93659</EventRecordID>
    <Channel>Application</Channel>
    <Computer>****</Computer>
    <Security />
  </System>
  <EventData>
    <Data>Fiddler.exe</Data>
    <Data>4.6.3.50306</Data>
    <Data>584b0128</Data>
    <Data>KERNELBASE.dll</Data>
    <Data>10.0.16299.15</Data>
    <Data>4736733c</Data>
    <Data>e0434352</Data>
    <Data>0000000000013fb8</Data>
    <Data>10b98</Data>
    <Data>01d399a11c497360</Data>
    <Data>C:\Program Files (x86)\Fiddler2\Fiddler.exe</Data>
    <Data>C:\WINDOWS\System32\KERNELBASE.dll</Data>
    <Data>021dcf44-7589-4944-a00d-8f3eb1243ed8</Data>
    <Data>
    </Data>
    <Data>
    </Data>
  </EventData>
</Event>


Log Name:      Application
Source:        .NET Runtime
Date:          30.01.2018 11:05:36
Event ID:      1026
Task Category: None
Level:         Error
Keywords:      Classic
User:          N/A
Computer:      ****
Description:
Application: Fiddler.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.IO.FileNotFoundException
   at Fiddler.FiddlerApplication..cctor()


Exception Info: System.TypeInitializationException
   at Fiddler.FiddlerApplication.ReportException(System.Exception, System.String)
   at Fiddler.CONFIG..cctor()


Exception Info: System.TypeInitializationException
   at Fiddler.frmViewer.•(System.Object, System.UnhandledExceptionEventArgs)




Event Xml:
<Event xmlns='http://schemas.microsoft.com/win/2004/08/events/event'><System><Provider Name='.NET Runtime'/><EventID Qualifiers='0'>1026</EventID><Level>2</Level><Task>0</Task><Keywords>0x80000000000000</Keywords><TimeCreated SystemTime='2018-01-30T08:05:36.981296100Z'/><EventRecordID>93658</EventRecordID><Channel>Application</Channel><Computer>****</Computer><Security/></System><EventData><Data>Application: Fiddler.exe
Framework Version: v4.0.30319
Description: The process was terminated due to an unhandled exception.
Exception Info: System.IO.FileNotFoundException
   at Fiddler.FiddlerApplication..cctor()


Exception Info: System.TypeInitializationException
   at Fiddler.FiddlerApplication.ReportException(System.Exception, System.String)
   at Fiddler.CONFIG..cctor()


Exception Info: System.TypeInitializationException
   at Fiddler.frmViewer.•(System.Object, System.UnhandledExceptionEventArgs)


</Data></EventData></Event>

Hi!

Website sends data over websocket and I can see it under WebSocket tab (see fiddler1.png). My purpose was to get the message payloads to the file as ascii text. So I found https://www.codeproject.com/Articles/718660/Debug-Inspect-WebSocket-traffic-with-Fiddler. Now I see the websocket messages in the session window but script passes by where payload should be recognized as binary (see fiddler2.png) - condition

never became true. When I saved payload to file it looked binary to me.

Chrome -> Developer tools -> Network ->WS->Frames shows the payload data in JSON format. I would appreciate if anyone drops a hint where I am going wrong.

Hello,

I connect fiddler with IOS device. HTTPS is turned on, the certificate is installed couple times.

The connection is fine. I can see the tunnel to...:443. I can also see https/404... but nothing else.

When I started the App, it says unable to connect to the server.

Fiddler only has tunnel to...443. 

But for some reason, I was able to capture the traffic and log-in one time. well, only the once...

I am sure there is nothing different that time. I think Fiddler is acting wired...

Have any suggestion? thank you.

Sincerely,

Ts

Is there a way for an HTML-based tab extension to interact with Fiddler's list of sessions?

In file CustomRules.js, I created a new tab ...

For those who are not familiar with the above BindUITab feature: The tab returns an HTML-formatted string, which Fiddler then displays in the new tab as if it were a web page.  In my case, the displayed content is derived from the list of selected sessions that are provided by Fiddler as the arrSess function parameter.

I would like the HTML and JavaScript in my tab to affect the sessions in Fiddler's session list.  For example, when the user clicks on a certain part of my HTML, I would like the tab's JavaScript to cause a corresponding session in Fiddler's list to be highlighted.  Is this possible?

Put another way: When the HTML of my new tab is displayed, does Fiddler provide any interface or object to the JavaScript of the tab, so that the tab can interact back to Fiddler?

I love this HTML-based custom tab capability, because it allows my team to quickly and easily customize the tab's functionality for specific situations.  I just wish the tab could talk back to Fiddler ...

I wrote a simple .net windows form program using FiddlerCore (version 4.6.20172.35715)

It has only 2 lines in Form.Load

CONFIG.bEnableIPv6 = False
FiddlerApplication.Startup(8888, 520)

I needed a proxy server so I can browse the internet using my home's IP anywhere.

After 3 or 5 days, or even as long as a week, the proxy server stopped responding. If I close the .net program then run it again.

The proxy server works again.

Is there anything I could do to prevent this interruption?

This is by far the best proxy server I could find. Please shed some light on.

I have a problem. We have app requests header that contains symbols: Ø, ø; Æ, æ; Å, å. And when Fiddler this request I see in and see this in Inspectors in Fiddler:

Header: �rdal

How fix it?

Hi:

     I've been through this link(https://www.telerik.com/forums/how-to-send-multiple-requests-sequentially-using-fiddler-script) to know how to send multiple  HTTP requests using fiddler script.

     I want to know, how to use the script to resend if it's the websocket message.

     And another question, Does fiddler support to intercept and modify the websocket information if I don't use the script?

Any suggestions?

Hi,

Does anybody succeed to see Apple Music requests on the Android Application ?

I have no issue with HTTPS on many apps (already installed certificate on my android test mobile) also installed Xposed Framework to trying to remove SSL pinning but nothing to do... I can't see nothing.

Help really appreciated.

Could anybody please help me with the following issues of FiddlerCore?

I'm evaluating it for our use in products and have built a C# program to test it on win7 32/64 bit and Win10 64bit. It's based on the reference code from https://github.com/RickStrahl/WestWindWebSurge/blob/master/WebSurge/FiddlerCapture.cs but simplified with just hook up to BeforeRequest and BeforeResponse.

1. Memory leak - after processing 674 HTTP/HTTPS requests, Task Manager shows that my program uses 139MB memory. VS2017's Performance Profiler shows multiple memory allocation inside FiddlerCore which seem never being released.

2. CPU spike - in a win7 64bit environment, it consistently gives 80+% CPU usage.

3. Certificate installation does not always happens. Sometimes it seems that CertMaker.rootCertExists() or other related functions do not work correctly and the pop-up dialog is not shown.

4. I call "FiddlerApplication.Startup(8888, true, true, true);" to set Fiddler as the system-wide proxy. But the FidllerCore's log complains that "AutoProxy failed. Disabling for this network." Is it an issue here?

I'm using 4.6.20172.35715 and the above issues happen on both .net 2 and .net 4 libs.

Also, is there a doc for the interfaces and parameters, especially for the troubleshooting and performance tuning? Thanks.

When I go into settings and clicks on the "Decrypt HTTPS traffic" checkbox, Fiddler freezes and nothing happens no matter what I do. I am using v4.6.20172.34691 but I've tried with the newest version too, which has the same problem. It used to work last time I used it, and before i upgraded to the newest version. And there is no crash, it just freezes.