
I have to trace incoming https requests using fiddler. As per docs, we have to use fiddler as reverse proxy for which we need to make a change in registry.
In organization, touching registry manually is not allowed. Is there anyother way to enable the reverse proxy feature. Is there any button available in fiddler through which changes can be done automatically.
Please suggest. I need this on urgent basis.
Hi guys,
I'm getting the following error:
CONNECT :443 HTTP/1.1Host: :443A SSLv3-compatible ClientHello handshake was found. Fiddler extracted the parameters below.Version: 3.3 (TLS/1.2)Random: 0F 42 E4 A0 84 A5 05 4B 54 8C 2C 2B A1 F4 01 B8 9D 81 9A A8 74 FE 24 E8 46 15 19 68 3C BC 0E 01"Time": 16-07-2055 03:21:19SessionID: emptyHTTP/1.1 200 Connection EstablishedFiddlerGateway: DirectStartTime: 19:37:45.587Connection: closefiddler.network.https> HTTPS handshake to (for #1) failed. System.IO.IOException Received an unexpected EOF or 0 bytes from the transport stream.
I have trusted the fiddler root certificate, imported it via mmc. Further more I have set fiddler to ignore certificate errors, and enabled the following protocols:
<client>;ssl2;ssl3;tls1.0;tls1.1;tls1.2
I'm using fiddler 4.5, but have also tried with version 2.
I also tried searching for this issue, but no solution seemed to present itself. Usually adding tls1.2 worked for people, but not in my case :(

Hello,
I am getting the following error in fiddler and without Capture HTTPS CONNECTs it works, also in the Protocols I have enabled: <client>;ssl2;ssl3;tls1.0;tls1.1;tls1.2
fiddler.network.https> HTTPS handshake to <domain> (for #6) failed. System.Security.Authentication.AuthenticationException A call to SSPI failed, see inner exception. < The message received was unexpected or badly formatted
Win32 (SChannel) Native Error Code: 0x80090326
I have a fiddler capture and a netMon capture but don't wish to post that here.
Thank you,
Ahsen Baig
Hi, I'm running fiddler v5.0.20182.28034 for .NET 4.6.1 on Windows 10. When I start a capture or open an archive, after a couple minutes the session window automatically clears. I then have to either recapture my sessions or re-open the archive.
Is there a setting that is performing the automatic clearing? Seems to happen every couple minutes.
also note I don't see this behavior on Windows Server with the same version of fiddler.
thanks!

I knoiw a chrome plugin uses proxy for its communication
Can fiddler intercept that?
Hello, I followed the instructions, but got the below exception -
$ mono fiddler.exe
WARNING: The Carbon driver has not been ported to 64bits, and very few parts of Windows.Forms will work properly, or at all
Stacktrace:
at <unknown> <0xffffffff>
at (wrapper managed-to-native) System.Windows.Forms.XplatUICarbon.CGDisplayBounds (intptr) [0x00002] in <556a6ba2c0a546f1ad2318c309ce0945>:0
at System.Windows.Forms.XplatUICarbon.get_WorkingArea () [0x00005] in <556a6ba2c0a546f1ad2318c309ce0945>:0
at System.Windows.Forms.XplatUICarbon.get_VirtualScreen () [0x00000] in <556a6ba2c0a546f1ad2318c309ce0945>:0
at System.Windows.Forms.XplatUI.get_VirtualScreen () [0x00000] in <556a6ba2c0a546f1ad2318c309ce0945>:0
at System.Windows.Forms.Screen..cctor () [0x00034] in <556a6ba2c0a546f1ad2318c309ce0945>:0
at (wrapper runtime-invoke) object.runtime_invoke_void (object,intptr,intptr,intptr) [0x0001e] in <98fac219bd4e453693d76fda7bd96ab0>:0
at <unknown> <0xffffffff>
at System.Windows.Forms.Form.get_CreateParams () [0x00157] in <556a6ba2c0a546f1ad2318c309ce0945>:0
at System.Windows.Forms.Control.CreateHandle () [0x0002a] in <556a6ba2c0a546f1ad2318c309ce0945>:0
at System.Windows.Forms.Form.CreateHandle () [0x00000] in <556a6ba2c0a546f1ad2318c309ce0945>:0
at System.Windows.Forms.Control.CreateControl () [0x00039] in <556a6ba2c0a546f1ad2318c309ce0945>:0
at System.Windows.Forms.Control.SetVisibleCore (bool) [0x00057] in <556a6ba2c0a546f1ad2318c309ce0945>:0
at System.Windows.Forms.Form.SetVisibleCore (bool) [0x00065] in <556a6ba2c0a546f1ad2318c309ce0945>:0
at System.Windows.Forms.Control.set_Visible (bool) [0x00009] in <556a6ba2c0a546f1ad2318c309ce0945>:0
at System.Windows.Forms.Control.Show () [0x00000] in <556a6ba2c0a546f1ad2318c309ce0945>:0
at (wrapper remoting-invoke-with-check) System.Windows.Forms.Control.Show () [0x00031] in <556a6ba2c0a546f1ad2318c309ce0945>:0
at Fiddler.frmViewer.‹• (string[]) [0x00081] in <09623c708fdb40a483cea147bbea7a7f>:0
at Fiddler.frmViewer.‡• (string[]) [0x00016] in <09623c708fdb40a483cea147bbea7a7f>:0
at (wrapper runtime-invoke) <Module>.runtime_invoke_void_object (object,intptr,intptr,intptr) [0x0004e] in <09623c708fdb40a483cea147bbea7a7f>:0
exception inside UnhandledException handler: The type initializer for 'System.Windows.Forms.Screen' threw an exception.
[ERROR] FATAL UNHANDLED EXCEPTION: System.TypeInitializationException: The type initializer for 'System.Windows.Forms.Screen' threw an exception. ---> System.NullReferenceException: Object reference not set to an instance of an object
at (wrapper managed-to-native) System.Windows.Forms.XplatUICarbon.CGDisplayBounds(intptr)
at System.Windows.Forms.XplatUICarbon.get_WorkingArea () [0x00005] in <556a6ba2c0a546f1ad2318c309ce0945>:0
at System.Windows.Forms.XplatUICarbon.get_VirtualScreen () [0x00000] in <556a6ba2c0a546f1ad2318c309ce0945>:0
at System.Windows.Forms.XplatUI.get_VirtualScreen () [0x00000] in <556a6ba2c0a546f1ad2318c309ce0945>:0
at System.Windows.Forms.Screen..cctor () [0x00034] in <556a6ba2c0a546f1ad2318c309ce0945>:0
--- End of inner exception stack trace ---
at System.Windows.Forms.MessageBox+MessageBoxForm.InitFormsSize () [0x00002] in <556a6ba2c0a546f1ad2318c309ce0945>:0
at System.Windows.Forms.MessageBox+MessageBoxForm.RunDialog () [0x0000f] in <556a6ba2c0a546f1ad2318c309ce0945>:0
at (wrapper remoting-invoke-with-check) System.Windows.Forms.MessageBox+MessageBoxForm.RunDialog()
at System.Windows.Forms.MessageBox.Show (System.Windows.Forms.IWin32Window owner, System.String text, System.String caption, System.Windows.Forms.MessageBoxButtons buttons, System.Windows.Forms.MessageBoxIcon icon) [0x0000b] in <556a6ba2c0a546f1ad2318c309ce0945>:0
at Fiddler.FiddlerApplication.DoNotifyUser (System.Windows.Forms.IWin32Window ownerWnd, System.String sMessage, System.String sTitle, System.Windows.Forms.MessageBoxIcon oIcon) [0x0002c] in <09623c708fdb40a483cea147bbea7a7f>:0
at Fiddler.FiddlerApplication.DoNotifyUser (System.String sMessage, System.String sTitle, System.Windows.Forms.MessageBoxIcon oIcon) [0x00000] in <09623c708fdb40a483cea147bbea7a7f>:0
at Fiddler.FiddlerApplication.ReportException (System.Exception eX, System.String sTitle, System.String sCallerMessage) [0x001a4] in <09623c708fdb40a483cea147bbea7a7f>:0
at Fiddler.FiddlerApplication.ReportException (System.Exception ‚) [0x00006] in <09623c708fdb40a483cea147bbea7a7f>:0
at Fiddler.frmViewer.• (System.Object, System.UnhandledExceptionEventArgs •) [0x00006] in <09623c708fdb40a483cea147bbea7a7f>:0

Hey everyone, I am new to this forum. I've been capturing HTTPS traffic of my web browser without a problem. Now I want to test my command line application which makes requests to an HTTPS server. I've installed FiddlerRoot.cer on my Windows machine, browsers work fine but my app doesn't. It gives handsahke error. I guess I need to provide some certificate to my HttpClient in the code. I don't have deep experiences with certificates and certificate types. Dart language guidelines explains some points but I can't understand. As far as I see, Dart accepts PKCS#12.
Dart tutorial for using certificates: https://dart-lang.github.io/server/tls-ssl.html
My code question on the StackOverflow: https://stackoverflow.com/questions/54278013/certificate-error-when-analyzing-https-traffic-with-fiddler

Just wanted to point out you need to run the 32-bit version of mono to get this to launch without errors. The maintainers should probably point out that on the Mac download page.
To run it, you need to do a:
'mono --arch=32 Fiddler.exe'
Dear all expert users,
I work with a web app having a specific issue working with Edge browsers. To inspect what happens, I wanted to monitor and debug with Fiddler, but I just can't make my Edge browser communicate with Fiddler2. My environment looks like this:
* Microsoft Edge 38.14393.0.0; proxy settings: Automatic
* Windows 10
* Fiddler v4.6.3.44034
* disabled Windows Firewall.
(1) Browsing in Edge with Fiddler off:
I can surf about as desired.
When I now inspect Edge proxy settings, they are set not to use a proxy. This is as expected.
(2) Starting Fiddler and trying again:
Any attempts to load a web page makes Edge complain, it can not connect to the proxy server (Fiddler).
This time, Edge proxy settings were changed after Edge restart. Now it's set to use 127.0.0.1:8888 for HTTP and HTTPS, as expected.
If I try opening another browser session from Fiddler, IE works well and Chrome works well. Only Edge does not connect to the proxy..
I read other threads on this forum, and found suggestions this might happen because of windows firewall, possibly even some hard coded matter in the firewall. However, as I stated above: My problem persist even with firewall turned on or off. Therefore my conclusion: Edge and Fiddler don't cooperate, and it has not to do with the firewall settings.
Uless of course, anyone is able to explain to me what happens or how to make things work. (It would typically be some simple setting I have got wrong, for sure.. You'd make me really happy, if you made me understand. :-)
Cheers,
Aril