When connecting direct with a particular website/request, everything runs happily, but as soon as Fiddler is introduced into the equation, a 504 Gateway Timeout occurs.

The request in question is an http request on port 443.

Is it an issue that can be fixed?

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Uncaught Exception in Session #1
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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.

Object reference not set to an instance of an object.

Type: System.NullReferenceException
Source: KennySpeeder
   at SpeedLimit.AutoTamperRequestBefore(Session oSession)

   at Fiddler.FiddlerExtensions.(Session ) in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Application\Extensions.cs:line 798

   at Fiddler.Session.() in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\Session.cs:line 5195

   at Fiddler.Session.‘() in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\Session.cs:line 3394

   at Fiddler.Session.(Object ) in C:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\Common\Core\Session.cs:line 3347


Fiddler v4.6.20171.14978 (x64 AMD64) [.NET 4.0.30319.18052 on Microsoft Windows NT 6.1.7601 Service Pack 1] 
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确定   
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The instructions on http://www.telerik.com/blogs/fiddler-for-linux-beta-is-here for installing Fiddler for Linux Beta mention running /usr/lib/mono//mozroots --import --sync. However I don't have that application. Instead, mozroot is to be found in /usr/lib/mono/4.5. The documentation might confuse some folk.

For info, Linux Mint 18.1. Mono installed through apt install mono-complete.

Just a quick aside, why does the forum sign-up insist on the user entering a company name? We don't all work for companies.

Hi.

 

I get the following exception when I want to repeat a request via Shift + R

Once I press OK, the process continues with Repeat Count prompt and the repetition works.

 

Thanks

 

---------------------------
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.

Value of 'null' is not valid for 'stream'.

Type: System.ArgumentException
Source: System.Drawing
   at System.Drawing.Image.FromStream(Stream stream, Boolean useEmbeddedColorManagement, Boolean validateImageData)

   at Fiddler.frmPrompt.GetUserString(IWin32Window wndOwner, String sTitle, String sPrompt, String sDefault, Boolean bReturnNullIfCancelled, PromptIcon piIcon) in c:\JenkinsHome\jobs\FiddlerReleaseBuild\workspace\Fiddler2\frmPrompt.cs:line 84


Fiddler v4.6.3.50306 (x64 AMD64) [.NET 4.0.30319.42000 on Microsoft Windows NT 6.1.7601 Service Pack 1]
---------------------------
OK   
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I have the following scenario: There are a OPTIONS and a GET request for the same URL. I want to use the AutoResponder to only modify the GET request. How can that be accomplished in terms of setting up the correct rule?

Hello,

I have a packet capture which throws error while importing to Fiddler. I have selected one packet from capture and uploaded the capture to https://www.sendspace[.]com/file/rqnqs9 to find our what is different about this capture from the other usual captures that I am able to import without any problems. I have also attached the error screenshot that I get while I import this capture. Please feel free to delete this thread if this is not appropriate to be asked here. 

Regards,

Rohit

I am a longtime user of Fiddler (version 2) proxy and it really is an amazing product. One of it's best features is the ability to decode and inspect HTTPS traffic, including automatic generation of proper certificates. Usually this works without problems, but I've stumbled upon a problem, which is not clear to me.

I am trying to "convince" some java program, which connects to it's server via https, to use Fiddler2 as a proxy (on Windows 7 x64, java 1.6.0_45 64-bit). Java program itself just won't connect through proxy, regardless of what I do or set up via Java control panel. I cannot modify the java source code (not available) or add command line parameters to java because it's started inside a parent .exe program. The only thing I could come up was to use a "proxifier" (ProxyCap), which redirects all traffic from any program (system wide) to a configured Fiddler2 proxy.

If I now test the existing configuration with my own java program (proxified) issuing https requests, I can see the decoded https traffic in Fiddler2 (first tunnel set up, then decoded traffic). If I run the original java program, I can see it sets up the tunnel to the destination IP, but then nothing happens. In request headers I see CONNECT <IP>:443 and in response I see "200 Connection Established".

Is Fiddler2 behaving differently to the application itself as the original https server would? Could an application (java program) stop because the parameters exchanged during the handshake are not the "correct" ones? Or is Fiddler connecting to the remote https server in a "wrong" way and it disconnects it? How can I get more information about what's happening?

Fiddler is not capturing requests from an online game website anymore, I think its because the game has used SSL to block the requests from capturing. Is there any way to still capture and modify them even though the site has somehow prevented Fiddler from doing so?

After clicking on Tools | HTTPS | Capture HTTPS CONNECTS, the minute I click the box next to Decrypt HTTPs traffic Fiddler throws the following error:

makecert.exe returned - 1.

Results from c:\program files (x86)\Fiddler2\MakeCert.exe -r -ss my -n
"CN=DO_NOT_TRUST_FiddlerRoot,    etc, etc

Error:  Can't create the key of the subject ('JoeSoft')
Failed

See attached screenshot.

When I try to export the Root Certificate to the Desktop it throws the following error:
The root certificate could not be located.

OS:  Win8.1

im using windows 8.1, when trying to install certificate to decrypt traffic,i get this error Failed to find the root certificate in User Root List.