I am trying to capture API endpoints by enabling fiddler capture, however, my application do not proceed, instead, it throws an error as ERR_EMPTY_RESPONSE.

 

If I disconnect the Fiddler application works fine, but then I am unable to capture the request/response

Ive been getting this error about once a day and fiddler will crash. Im stuck on this and have no more ideas what i can do. 

im trying fiddler classic ( also might be called fiddler 4? im not sure)

 

Progress Telerik Fiddler Web Debugger

v5.0.20204.45441 for .NET 4.6.1
Built: Tuesday, November 03, 2020

64-bit AMD64, VM: 110.0mb, WS: 141.0mb
.NET 4.8 WinNT 6.1.7601 SP1

 

 

Any ideas?

Thanks

I have a problem with cert while using fiddler with android and I finally found the best solution. Change cert to generated by plug-in fiddlercertmaker.exe. By the way, anything in window such as Firefox browser fail to work properly with this type of cert. I already trust install and all. Can I set the system to use original fiddler cert when I use windows's process e.g. Firefox, or specific domain. Even by scripting in Fiddler Script, any solution is fine that I can use fiddler with browser too if solution exists.

 

Some website is accessible but it completely not in session list table, some of them cant access at all.

This is the whole error text (facebook):

Did Not Connect: Potential Security Issue

Firefox detected a potential security threat and did not continue to www.facebook.com because this website requires a secure connection.

What can you do about it?

www.facebook.com has a security policy called HTTP Strict Transport Security (HSTS), which means that Firefox can only connect to it securely. You can’t add an exception to visit this site.

The issue is most likely with the website, and there is nothing you can do to resolve it.

If you are on a corporate network or using anti-virus software, you can reach out to the support teams for assistance. You can also notify the website’s administrator about the problem.

As title.  If the firewall is disabled, we are able to start Fiddler no problem.  If the firewall is enabled, I get the following popup when it tries to start.

 

What could be the issue here?

----------------------8<-------------------

 

Awww, Fiddlesticks!
---------------------------
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.

The composition produced a single composition error. The root cause is provided below. Review the CompositionException.Errors property for more detailed information.



1) The specified quota list is internally inconsistent with its descriptor



Resulting in: An exception occurred while trying to create an instance of type 'Telerik.NetworkConnections.NetworkConnectionsManager'.



Resulting in: Cannot activate part 'Telerik.NetworkConnections.NetworkConnectionsManager'.

Element: Telerik.NetworkConnections.NetworkConnectionsManager -->  Telerik.NetworkConnections.NetworkConnectionsManager -->  AssemblyCatalog (Assembly="Telerik.NetworkConnections, Version=0.1.2.0, Culture=neutral, PublicKeyToken=67cb91587178ac5a")



Resulting in: Cannot get export 'Telerik.NetworkConnections.NetworkConnectionsManager (ContractName="Telerik.NetworkConnections.NetworkConnectionsManager")' from part 'Telerik.NetworkConnections.NetworkConnectionsManager'.

Element: Telerik.NetworkConnections.NetworkConnectionsManager (ContractName="Telerik.NetworkConnections.NetworkConnectionsManager") -->  Telerik.NetworkConnections.NetworkConnectionsManager -->  AssemblyCatalog (Assembly="Telerik.NetworkConnections, Version=0.1.2.0, Culture=neutral, PublicKeyToken=67cb91587178ac5a")



Type: System.ComponentModel.Composition.CompositionException
Source: System.ComponentModel.Composition
   at System.ComponentModel.Composition.Hosting.CompositionServices.GetExportedValueFromComposedPart(ImportEngine engine, ComposablePart part, ExportDefinition definition)

   at System.ComponentModel.Composition.Hosting.CatalogExportProvider.GetExportedValue(CatalogPart part, ExportDefinition export, Boolean isSharedPart)

   at System.ComponentModel.Composition.Primitives.Export.get_Value()

   at System.ComponentModel.Composition.ExportServices.GetCastedExportedValue[T](Export export)

   at Fiddler.Proxy.() in C:\Jenkins\Fiddler_Windows\workspace\FiddlerCore\FiddlerCore.Shared\Common\Core\Proxy.cs:line 283

   at Fiddler.Proxy..ctor(Boolean isPrimary, ProxySettings upstreamProxySettings) in C:\Jenkins\Fiddler_Windows\workspace\FiddlerCore\FiddlerCore.Shared\Common\Core\Proxy.cs:line 210

   at Fiddler.frmViewer.‹•(String[] ˆ•) in C:\Jenkins\Fiddler_Windows\workspace\Fiddler2\Fiddler.Shared\Viewer.cs:line 3339

   at Fiddler.frmViewer.‡•(String[] ˆ•) in C:\Jenkins\Fiddler_Windows\workspace\Fiddler2\Fiddler.Shared\Viewer.cs:line 3168


Fiddler v5.0.20211.51073 (x64 AMD64) [.NET 4.0.30319.42000 on Microsoft Windows NT 10.0.19042.0]

I need keep sending command FiddlerObject.utilIssueRequest(url);  and read result for stop command and stop working when the required result is achieved

example

stop1  if Body = 170 => send FiddlerObject.utilIssueRequest(url);

stop2  if Body = 170 => send FiddlerObject.utilIssueRequest(url);

stop3  if Body = 310 => send FiddlerObject.utilIssueRequest(url);

 

I am trying to capture traffic using Fiddler from an Android app running on an emulator (I am using MuMu).  I got most of what I was trying to accomplish. I added the required cert to Android and I can see most http/https traffic fine.

 

The issue I am facing is that I cannot see requests from the app that go to http://127.0.0.1:26284. I understand that the localhost for the Android emulator is different than my machine which is running Fiddler. I did some searching and found info on Android networking (https://developer.android.com/studio/run/emulator-networking) and 10.0.0.2 but I am not sure how to use that info or if it is even relevant to my issue.

 

For what I do have working, I set the proxy in the emulator to my actual machine's address (the one running Fiddler) and set it to bypass the proxy for 127.0.0.1 (otherwise the app wouldn't work as the calls to localhost would fail).

 

My goal is to be able to see the request/responses on the emulators localhost. Is it possible via Fiddler?  Maybe adding some redirects or something like that, just so I can see the request/response? Or any other way at all? I do not have access to change the calls in the app that go to 127.0.0.1.

 

Please let me know if there is any additional info that I can give that may help. This is my first time working with emulators and proxies.

How to use it utilIssueRequest();

I'm a Fiddler Classic user and I would like to know if it's possible to read a local text file into a variable.

I will use this variable (say, 'file_contents') to replace a string in a web page with the contents of the local file. The replacement code looks like this:
How can I do that, please?

Thank you,

Alexander

FiddlerCore4 can't handle the traffic coming from xNet.dll library, how can I fix it, I really need help.

... As far as I know, any traffic going through the SOCKS5 proxy will not be logged by Fiddlercore (because Fiddler does not support traffic collection over the SOCKS proxy). So how can I fix that on Fiddlercore, I use C#.