I have a .net app (using framework 4.7.1) making a simple call to fetch images from various sites. One site for some reason will always timeout the request. But if I use Fiddler as a proxy, then it always works just fine. The image URL also works just fine in a browser. I'm aware of the various things to look for when Fiddler seems to 'fix' your app, but none of them seem to apply here. I have tried using different protocols in options ... https ... protocols to see if I could get Fiddler to also fail in the same way, but no luck, it always succeeds. Even if I uncheck 'capture https connects' it works. 

Any ideas what Fiddler could be doing to make it work so I can fix my app?

New to packet sniffing and network diagnostics ..... I have what I hope to be a simple request.

1.  I want to do some automation. However, I do not want to use cloud based only solutions.

2.  At the moment I have not particular tech in mind but it will be wifi ... as I do not have a smart home hub for zig-bee or z-wave or what have you.

3.  Thinking about starting here with this product: https://www.amazon.com/SmartDry-Wireless-Laundry-Clothes-Electric/dp/B07GQBW2KS/ref=pd_ybh_a_1?_encoding=UTF8&psc=1&refRID=1PES8E33EBRMBXN9BDVX

4.  Now it's wifi based and that means it has to go through my router to work.  Which means, I think, it should be simple url based traffic.  Can fiddler on my laptop be set up to intercept the traffic coming in to a smart phone and out of smartphone and in/out of my net work ( yes I'd have the phone set to use wifi data not phone data plan )


If there is a tutorial out there that more/less ( aka more ) discusses this I'd be grateful.  I'm struggling to get going with automation because it seems that every Tom, Dick, and Harry company just wants you to create an account so that they can pimp your data around.  I'd rather pay say $20 more for the tech rather than have to crack open my personal data.

I started up Fiddler, set it to show all connections, and got a ton.

But when I used Chrome to get the file https://www.davidthielen.info/files/dave.docx - nothing in Fiddler. I also tried http://www.davidthielen.info/files/dave.docx

Is there some additional settings to show file downloads?

thanks - dave

So, first let me apologize for being in way over my head.  Now that that's out of the way....

I was wondering if someone could maybe help me explain why an API call made from .NET (specifically the Invoke-RestMethod cmdlet in powershell) might return a 401 Auth Error when executed without fiddler, but return data as expected while fiddler is open?  This behavior occurs using both HTTP and HTTPS (I found an article from way back mentioning Fiddler used a specific TLS regardless of the client request, but this does not seem to be the case anymore).

I've typically only interacted with this particular API via PHP and cURL, but I needed a windows application.

It would seem to me that the explanation is that Fiddler is somehow modifying the request my application is sending, but I have no idea how to look for that.

If this isn't the correct place for this question, my bad.

 

Hello forum


does FiddlerCap capture all 7 OSI Layers or only "connections" ?


Thank you!

Joe

Hi -- I tried installing Fiddler Everywhere for my MBP and i enabled Capture HTTPS Traffic and trusted the root Certificate also. I am still not able to capture the traffic in Fiddler.

hello fiddler4's latest update can't decompress https://bit.ly/2ZkNmAk this link's content

Подробная информация об использовании оперативной 
(JIT) отладки вместо данного диалогового 
окна содержится в конце этого сообщения.

************** Текст исключения **************
System.NullReferenceException: Ссылка на объект не указывает на экземпляр объекта.
   в Fiddler.frmViewer.š(Object , EventArgs ) в C:\Jenkins\Fiddler_Windows\workspace\Fiddler2\Fiddler.Shared\Viewer.cs:строка 9983
   в System.Windows.Forms.Form.OnLoad(EventArgs e)
   в System.Windows.Forms.Form.OnCreateControl()
   в System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
   в System.Windows.Forms.Control.CreateControl()
   в System.Windows.Forms.Control.WmShowWindow(Message& m)
   в System.Windows.Forms.Control.WndProc(Message& m)
   в System.Windows.Forms.ScrollableControl.WndProc(Message& m)
   в System.Windows.Forms.Form.WmShowWindow(Message& m)
   в System.Windows.Forms.Form.WndProc(Message& m)
   в Fiddler.frmViewer.WndProc(Message& m) в C:\Jenkins\Fiddler_Windows\workspace\Fiddler2\Fiddler.Shared\Viewer.cs:строка 12465
   в System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   в System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   в System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)


************** Загруженные сборки **************
mscorlib
    Версия сборки: 4.0.0.0
    Версия Win32: 4.0.30319.235 (RTMGDR.030319-2300)
    CodeBase: file:///C:/WINDOWS/Microsoft.NET/Framework/v4.0.30319/mscorlib.dll
----------------------------------------
Fiddler
    Версия сборки: 5.0.20202.18177
    Версия Win32: 5.0.20202.18177
    CodeBase: file:///C:/Program%20Files/Fiddler/Fiddler.exe
----------------------------------------
System
    Версия сборки: 4.0.0.0
    Версия Win32: 4.0.30319.232 built by: RTMGDR
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System/v4.0_4.0.0.0__b77a5c561934e089/System.dll
----------------------------------------
System.Core
    Версия сборки: 4.0.0.0
    Версия Win32: 4.0.30319.1 built by: RTMRel
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Core/v4.0_4.0.0.0__b77a5c561934e089/System.Core.dll
----------------------------------------
System.Windows.Forms
    Версия сборки: 4.0.0.0
    Версия Win32: 4.0.30319.235 built by: RTMGDR
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Windows.Forms/v4.0_4.0.0.0__b77a5c561934e089/System.Windows.Forms.dll
----------------------------------------
System.Drawing
    Версия сборки: 4.0.0.0
    Версия Win32: 4.0.30319.1 built by: RTMRel
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Drawing/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Drawing.dll
----------------------------------------
Telerik.NetworkConnections
    Версия сборки: 0.1.2.0
    Версия Win32: 0.1.2.0
    CodeBase: file:///C:/Program%20Files/Fiddler/Telerik.NetworkConnections.DLL
----------------------------------------
System.Configuration
    Версия сборки: 4.0.0.0
    Версия Win32: 4.0.30319.1 (RTMRel.030319-0100)
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Configuration/v4.0_4.0.0.0__b03f5f7f11d50a3a/System.Configuration.dll
----------------------------------------
System.Xml
    Версия сборки: 4.0.0.0
    Версия Win32: 4.0.30319.1 built by: RTMRel
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Xml/v4.0_4.0.0.0__b77a5c561934e089/System.Xml.dll
----------------------------------------
mscorlib.resources
    Версия сборки: 4.0.0.0
    Версия Win32: 4.0.30319.235 (RTMGDR.030319-2300)
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/mscorlib.resources/v4.0_4.0.0.0_ru_b77a5c561934e089/mscorlib.resources.dll
----------------------------------------
Xceed.Zip.v5.4
    Версия сборки: 5.4.13572.13590
    Версия Win32: 5.4.13572.13590
    CodeBase: file:///C:/Program%20Files/Fiddler/Xceed.Zip.v5.4.DLL
----------------------------------------
Xceed.Compression.Formats.v5.4
    Версия сборки: 5.4.13572.13590
    Версия Win32: 5.4.13572.13590
    CodeBase: file:///C:/Program%20Files/Fiddler/Xceed.Compression.Formats.v5.4.DLL
----------------------------------------
Xceed.Compression.v5.4
    Версия сборки: 5.4.13572.13590
    Версия Win32: 5.4.13572.13590
    CodeBase: file:///C:/Program%20Files/Fiddler/Xceed.Compression.v5.4.DLL
----------------------------------------
Xceed.FileSystem.v5.4
    Версия сборки: 5.4.13572.13590
    Версия Win32: 5.4.13572.13590
    CodeBase: file:///C:/Program%20Files/Fiddler/Xceed.FileSystem.v5.4.DLL
----------------------------------------
System.Windows.Forms.resources
    Версия сборки: 4.0.0.0
    Версия Win32: 4.0.30319.235 built by: RTMGDR
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.Windows.Forms.resources/v4.0_4.0.0.0_ru_b77a5c561934e089/System.Windows.Forms.resources.dll
----------------------------------------
System.ComponentModel.Composition
    Версия сборки: 4.0.0.0
    Версия Win32: 4.0.30319.1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.ComponentModel.Composition/v4.0_4.0.0.0__b77a5c561934e089/System.ComponentModel.Composition.dll
----------------------------------------
Telerik.NetworkConnections.Windows
    Версия сборки: 0.1.2.0
    Версия Win32: 0.1.2.0
    CodeBase: file:///C:/PROGRAM%20FILES/FIDDLER/PLUGINS/NETWORKCONNECTIONS/TELERIK.NETWORKCONNECTIONS.WINDOWS.DLL
----------------------------------------
MetadataViewProxies_1e031cd0-3f35-4522-83aa-273e160f99e6
    Версия сборки: 0.0.0.0
    Версия Win32: 4.0.30319.1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.ComponentModel.Composition/v4.0_4.0.0.0__b77a5c561934e089/System.ComponentModel.Composition.dll
----------------------------------------
System.ComponentModel.Composition.resources
    Версия сборки: 4.0.0.0
    Версия Win32: 4.0.30319.1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System.ComponentModel.Composition.resources/v4.0_4.0.0.0_ru_b77a5c561934e089/System.ComponentModel.Composition.resources.dll
----------------------------------------
Standard
    Версия сборки: 2.6.2.0
    Версия Win32: 2.6.2.0
    CodeBase: file:///C:/Program%20Files/Fiddler/Inspectors/Standard.dll
----------------------------------------
SyntaxView
    Версия сборки: 2.6.2.0
    Версия Win32: 2.6.2.0
    CodeBase: file:///C:/Program%20Files/Fiddler/Inspectors/SyntaxView.dll
----------------------------------------
FiddlerOrchestra.Addon
    Версия сборки: 1.0.20202.16135
    Версия Win32: 1.0.20202.16135
    CodeBase: file:///C:/Program%20Files/Fiddler/Scripts/FiddlerOrchestra.Addon.dll
----------------------------------------
FiddlerOrchestra.Connection
    Версия сборки: 1.0.20202.16135
    Версия Win32: 1.0.20202.16135
    CodeBase: file:///C:/Program%20Files/Fiddler/Scripts/FiddlerOrchestra.Connection.dll
----------------------------------------
netstandard
    Версия сборки: 2.0.0.0
    Версия Win32: 4.6.26011.1
    CodeBase: file:///C:/Program%20Files/Fiddler/Scripts/netstandard.DLL
----------------------------------------
FiddlerOrchestra.Protocol
    Версия сборки: 1.0.20202.16135
    Версия Win32: 1.0.20202.16135
    CodeBase: file:///C:/Program%20Files/Fiddler/Scripts/FiddlerOrchestra.Protocol.dll
----------------------------------------
FiddlerOrchestra.Utilities
    Версия сборки: 1.0.20202.16135
    Версия Win32: 1.0.20202.16135
    CodeBase: file:///C:/Program%20Files/Fiddler/Scripts/FiddlerOrchestra.Utilities.dll
----------------------------------------
RulesTab2
    Версия сборки: 2.6.2.0
    Версия Win32: 2.6.2.0
    CodeBase: file:///C:/Program%20Files/Fiddler/Scripts/RulesTab2.dll
----------------------------------------
SimpleFilter
    Версия сборки: 2.6.2.0
    Версия Win32: 2.6.2.0
    CodeBase: file:///C:/Program%20Files/Fiddler/Scripts/SimpleFilter.dll
----------------------------------------
Timeline
    Версия сборки: 2.6.0.3
    Версия Win32: 2.6.0.3
    CodeBase: file:///C:/Program%20Files/Fiddler/Scripts/Timeline.dll
----------------------------------------
Microsoft.JScript
    Версия сборки: 10.0.0.0
    Версия Win32: 10.0.30319.1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/Microsoft.JScript/v4.0_10.0.0.0__b03f5f7f11d50a3a/Microsoft.JScript.dll
----------------------------------------
JScript Thunk Assembly
    Версия сборки: 0.0.0.0
    Версия Win32: 10.0.30319.1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/Microsoft.JScript/v4.0_10.0.0.0__b03f5f7f11d50a3a/Microsoft.JScript.dll
----------------------------------------
83GejTrl
    Версия сборки: 0.0.0.0
    Версия Win32: 10.0.30319.1
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/Microsoft.JScript/v4.0_10.0.0.0__b03f5f7f11d50a3a/Microsoft.JScript.dll
----------------------------------------
bwpclfjs
    Версия сборки: 4.0.0.0
    Версия Win32: 4.0.30319.232 built by: RTMGDR
    CodeBase: file:///C:/WINDOWS/Microsoft.Net/assembly/GAC_MSIL/System/v4.0_4.0.0.0__b77a5c561934e089/System.dll
----------------------------------------

************** Оперативная отладка (JIT) **************
Для подключения оперативной (JIT) отладки файл .config данного
приложения или компьютера (machine.config) должен иметь
значение jitDebugging, установленное в секции system.windows.forms.
Приложение также должно быть скомпилировано с включенной
отладкой.

Например:

<configuration>
    <system.windows.forms jitDebugging="true" />
</configuration>

При включенной отладке JIT любое необрабатываемое исключение
пересылается отладчику JIT, зарегистрированному на данном компьютере,
вместо того чтобы обрабатываться данным диалоговым окном.

Hi, 

I'm trying to watch the API calls that my app is doing using Fiddler, I was able to do it in Android Phone, iOS, but not in Android TV box. 

For some reason, the .crt file is not being installed in the device. When I try to install it, the box shows me a message saying "Certificate not installed", so I'm not being able to capture the API calls. 



Did someone make Fiddler work in Android TV devices?

 

Thanks. 

Hi,

I am a newbie in using fiddler. I was trying to capture the HTTPS traffic from android app. I have installed the fiddler root certificate successfully on my android device but not able to capture the https traffic but  i see http calls going through tunnel.

Fiddler version : v5.0.20192.25091

Android OS version : 8.1.0

Please see the attached image for the fiddler settings applied and let me know if needed any more information.

Thanks