Fiddler crashes with Mono exception at launch

[Tibor]

```

bash-4.3# mono Fiddler.exe
exception inside UnhandledException handler: The type initializer for 'Fiddler.CONFIG' threw an exception.

[ERROR] FATAL UNHANDLED EXCEPTION: System.TypeInitializationException: The type initializer for 'System.Windows.Forms.XplatUI' threw an exception. ---> System.TypeInitializationException: The type initializer for 'System.Drawing.GDIPlus' threw an exception. ---> System.DllNotFoundException: libgdiplus.so.0
  at (wrapper managed-to-native) System.Drawing.GDIPlus:GdiplusStartup (ulong&,System.Drawing.GdiplusStartupInput&,System.Drawing.GdiplusStartupOutput&)
  at System.Drawing.GDIPlus..cctor () [0x000cc] in <1917aa1c39d94b1a91807b8cd9f03350>:0
   --- End of inner exception stack trace ---
  at System.Drawing.KnownColors..cctor () [0x0001a] in <1917aa1c39d94b1a91807b8cd9f03350>:0
   --- End of inner exception stack trace ---
  at System.Windows.Forms.Application.EnableVisualStyles () [0x00006] in <d5b72d15d4f7424c8a1538e3f19ec2e3>:0
  at Fiddler.frmViewer.ÂÂ (System.String[] ÂÂ) [0x00040] in <1f5c91af40d14c0eb3b0cb76da0ecdcc>:0                                                                                                                                                                               
  at Fiddler.frmViewer.ÂÂ (System.String[] ÂÂ) [0x00016] in <1f5c91af40d14c0eb3b0cb76da0ecdcc>:0

```

 

Slackware64_14.2

Mono JIT compiler version 4.6.2 (Stable 4.6.2.7/08fd525 Thu Feb  2 14:37:53 CET 2017)

[Tibor]

Nevermind, installed libgdiplus from https://slackware.pkgs.org/14.2/slackpack-x86_64/libgdiplus-4.2-x86_64-1gds.txz.html and it launches, but there's a subsequent error

It starts up the loading screen and then drops with this being the only output i get:

```

bash-4.3# mono Fiddler.exe
can not parse as value of type 'i':
  ""
  ^^
can not parse as value of type 'i':
  ""
  ^^

```

It still seems to be running as a process, because the commandline is responsive, but the GUI disappears

[Tibor]

Ok, i've done ldconfig and rebooted my machine, it seems to be running fine for now.

I will keep this thread updated if there are any more errors occurring.

[Tibor]

I need an answer to one question I don't seem to be able to find online.

 

Is there an option to bind fiddler to certain interface? e.g. wlan0

Since Fiddler.exe is not compliant with UNIX standards (no --help option or man entry) I was unable to deduct this information from the application directly.

[Tsviatko Yovtchev]

Sadly, at present there is no such option. 

Regards,
Tsviatko Yovtchev
Progress Telerik

[Tibor]

Thank you for your reply.

Do you plan on implementing the future later on? (Unfortunately because of this I find mitmproxy or wireshark much more comfortable and suited for this purpose)

[Tsviatko Yovtchev]

We have it on our backlog for sure. We cannot commit to a release deadline, however.

Regards,
Tsviatko Yovtchev
Progress Telerik

[Kamal]

Hi, I am trying to install Fiddler in Redhat-6.8 which is similar to Centos :

Steps followed as per blog installed mono package & it's working,

[root@test]# mcs hello.cs
[root@test]# ls
hello.cs  hello.exe
[root@test]# mono hello.exe
Hello Mono World

[root@test]# /usr/lib/mono/mozroots --import --sync
Mozilla Roots Importer - version 5.0.1.1
Download and import trusted root certificates from Mozilla's MXR.
Copyright 2002, 2003 Motus Technologies. Copyright 2004-2008 Novell. BSD licensed.
WARNING: mozroots is deprecated, please move to cert-sync instead.
Downloading from 'https://hg.mozilla.org/releases/mozilla-release/raw-file/default/security/nss/lib/ckfw/builtins/certdata.txt'...
Importing certificates into user store...
190 new root certificates were added to your trust store.
Import process completed.

but output of command mono fiddler.exe gives error shown below :

[root@test Fiddler]# mono Fiddler.exe
exception inside UnhandledException handler: The type initializer for 'System.Windows.Forms.WindowsFormsSynchronizationContext' threw an exception.
[ERROR] FATAL UNHANDLED EXCEPTION: System.TypeInitializationException: The type initializer for 'System.Windows.Forms.XplatUI' threw an exception. ---> System.ArgumentNullException: Could not open display (X-Server required. Check your DISPLAY environment variable)
Parameter name: Display
  at System.Windows.Forms.XplatUIX11.SetDisplay (System.IntPtr display_handle) [0x00408] in <298fc9b739c74aebb706be1d082ed5e4>:0
  at System.Windows.Forms.XplatUIX11..ctor () [0x00077] in <298fc9b739c74aebb706be1d082ed5e4>:0
  at System.Windows.Forms.XplatUIX11.GetInstance () [0x00019] in <298fc9b739c74aebb706be1d082ed5e4>:0
  at System.Windows.Forms.XplatUI..cctor () [0x00066] in <298fc9b739c74aebb706be1d082ed5e4>:0
   --- End of inner exception stack trace ---
  at System.Windows.Forms.Theme.get_MenuAccessKeysUnderlined () [0x00000] in <298fc9b739c74aebb706be1d082ed5e4>:0
  at System.Windows.Forms.SystemInformation.get_MenuAccessKeysUnderlined () [0x00005] in <298fc9b739c74aebb706be1d082ed5e4>:0
  at System.Windows.Forms.Control..ctor () [0x000e4] in <298fc9b739c74aebb706be1d082ed5e4>:0
  at (wrapper remoting-invoke-with-check) System.Windows.Forms.Control:.ctor ()
  at System.Windows.Forms.WindowsFormsSynchronizationContext..cctor () [0x00000] in <298fc9b739c74aebb706be1d082ed5e4>:0
[root@test Fiddler]#

 

My server doesn't have GUI interface.

 

=======

Thanks

[Alexander]

Hello Kamal,

Fiddler does not have a command-line interface and highly relies on the UI. Since your server does not have GUI it is not possible to run Fiddler there.

Regards,
Alexander
Progress Telerik

[Kamal]

Thanks,  Alexander

Application is running in GUI mode.

-----

Regards

Kamal Gangwani

[Alexander]

Hello again Kamal,

I'm writing you to let you know that now you can run the core of Fiddler - FiddlerCore without GUI on Linux. You can find more information here.

Regards,
Alexander
Progress Telerik