Unable to run Fiddler on Centos 7

[Flos]

---------------------------
System Error
---------------------------
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 given key was not present in the dictionary.

Type: System.Collections.Generic.KeyNotFoundException
Source: mscorlib
  at System.ThrowHelper.ThrowKeyNotFoundException () [0x00000] in /builddir/build/BUILD/mono-4.8.0/mcs/class/referencesource/mscorlib/system/throwhelper.cs:68
  at System.Collections.Generic.Dictionary`2[TKey,TValue].get_Item (TKey key) [0x00021] in <f712f98eb8e445c8918edaf595bbe465>:0
  at Fiddler.Proxy.RefreshUpstreamGatewayInformation () [0x000b4] in <bcca41f124814dd9a74204fd482fb6d7>:0
  at Fiddler.Proxy.CollectConnectoidAndGatewayInfo () [0x00017] in <bcca41f124814dd9a74204fd482fb6d7>:0


Fiddler v4.6.3.51842 (x64 ) [.NET 4.0.30319.42000 on Unix 3.10.0.514]
---------------------------
OK
---------------------------

 

Let me know if further steps I can help troubleshoot on this. Thanks.

[Tsviatko Yovtchev]

Hi,

Is this reproducible? Can you make it happen at will? If so what are the steps?

Regards,
Tsviatko Yovtchev
Telerik by Progress

[Adrian]

FYI, I see what appears to be the same error running Fedora 25 (with updates, uh, up to date).

---------------------------
System Error
---------------------------
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 given key was not present in the dictionary.

Type: System.Collections.Generic.KeyNotFoundException
Source: mscorlib
  at System.ThrowHelper.ThrowKeyNotFoundException () <0x41af2f30 + 0x0001f> in <filename unknown>:0
  at System.Collections.Generic.Dictionary`2[TKey,TValue].get_Item (System.Collections.Generic.TKey key) <0x4186f160 + 0x0004b> in <filename unknown>:0
  at Fiddler.Proxy.RefreshUpstreamGatewayInformation () <0x41af2ad0 + 0x00253> in <filename unknown>:0
  at Fiddler.Proxy.CollectConnectoidAndGatewayInfo () <0x41ae8670 + 0x0009f> in <filename unknown>:0


Fiddler v4.6.3.51842 (x64 ) [.NET 4.0.30319.42000 on Unix 4.9.13.200]
---------------------------
OK   
---------------------------

[Adrian]

Oh, steps to reproduce:

1. unzip fiddler-linux

2. mono Fiddler.exe

[Flos]

Hi Tsviatko, thanks for your attention. I can always reproduce this issue. Detailed steps as follows:

1. Newly install a Centos 7 with GNOME environment.

2. Follow the installation instructions "CentOS 7, Fedora 19 (and later), and derivatives" on mono project website:
  - http://www.mono-project.com/docs/getting-started/install/linux/
to install the mono-complete package. In my environment, it's mono-complete-4.8.0.495-0.xamarin.1.x86_64. Doing this step will install all the dependencies.

3. Download the fiddler for linux here:

  - https://www.telerik.com/download/fiddler

by clicking on "Check Out the Beta Build".

4. Create a directory in home directory:

$ mkdir ~/fiddler

$ cd ~/fiddler

and extract the fiddler-linux.zip to that direcotry.

5. Execute fiddler like this:

$ mono Fiddler.exe

6. The exception messages pop up.

[Tsviatko Yovtchev]

Hello,

What window managers are you guys running?

Regards,
Tsviatko Yovtchev
Telerik by Progress

[Adrian]

I was using Fedora's Gnome 3 desktop (non-wayland). However, for other reasons, I've switched to KDE Plasma -- and although I still get errors on startup, Fiddler appears to be working fine. Now if I can figure out how to import that certificate...

[Adrian]

Well, an error:

[Flos]

Hi,

I'm using MATE desktop. This issue is reproducable on the default GNOME 3.

Thanks,

Flos

[Tsviatko Yovtchev]

Hello,

We don't claim support for all window managers but we did our testing mostly on Gnome so that should be covered.

Could you, please, try the latest version we just released today. If it doesn't fix the rpoblem it should produce more detailed exception report.

Regards,
Tsviatko Yovtchev
Telerik by Progress

[Prashanth]

I have the latest version of Fiddler (Fiddler v4.6.20171.26113 (x64 )) running on Gnome manager (CentOS 6.9) and the same error is still popping up. With this error, Fiddler is unable to capture the traffic.

[Prashanth]

Exception is as below:

---------------------------
System Error
---------------------------
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 given key 'hardwareInterface' was not present in the dictionary.

Type: System.Collections.Generic.KeyNotFoundException
Source: mscorlib
  at System.Collections.Generic.Dictionary`2[TKey,TValue].get_Item (TKey key) [0x0001e] in <135e7c260ae04ab1a5538976c2d8cf31>:0
  at Fiddler.Proxy.Š‰ () [0x0009c] in <616b130fa1474630b442fde0f9112534>:0
  at Fiddler.Proxy.‰ () [0x00017] in <616b130fa1474630b442fde0f9112534>:0


Fiddler v4.6.20171.26113 (x64 ) [.NET 4.0.30319.42000 on Unix 2.6.32.696]
---------------------------
OK   
---------------------------

[Dimitar]

Hello Prashanth,

Sorry for the inconvenience caused.
To work around this issue you can manually set the proxy of your application/web browser to localhost ( 127.0.0.1 ) with port 8888.
After applying those changes, Fiddler will begin to capture the traffic from your web browser.
Please note that you have to manually convert back the proxy settings in order for the application/web browser to connect to the Internet.

Regards,
Dimitar
Progress Telerik