Re: Fiddler fails to start after IE10 update on Win7 64bit

[EricLaw]

Very interesting, thanks for reporting this problem. Inside Internet Explorer, please click Tools > Internet Options > Connections. Inside the "Dialup and VPN Connections" box, how many items are listed? Does your PC actually use any of the listed connections?

 

thanks!

[Tommy Lenz]

Eric,

I've got two vpn connections, neither of which are currently active. 

Not sure if it's important, but here are the LAN adapter settings:

 

Thanks for your help,

Tommy 

 

 

[EricLaw]

If you have a moment, can you try running this version: http://ericlawrence.com/dl/Fiddler4AlphaSetup.exe and, assuming it is able to startup properly, send me the content of the LOG tab after startup?

 

thanks!

[Tommy Lenz]

Uninstalled my existing copy, Installed from the link and same error.  When I choose to continue from the exception dialog, the app appears to be in an unstable state and must be forced to close.  In Fiddler Options...->Gateway, if I select No Proxy and try to Capture, I get an error message saying "Failed to register Fiddler as the system proxy."  Setting the gateway option back to User System Proxy returns the previous KeyNotFoundException.

[EricLaw]

Just to confirm, the version number you see for Fiddler.exe is 4.4.4.1?

[Tommy Lenz]

Correct.  4.4.4.1 beta in Help dialog

[EricLaw]

Something super-interesting is going wrong.

 

Please grab the latest from this link: http://ericlawrence.com/dl/Fiddler4alphasetup.Exe and send me the contents of the Log tab on startup. (It will still fail, but should provide information on why).

[Tommy Lenz]

Eric,

I don't have the Log tab available - perhaps as a result of an aborted startup sequence.(?)  The only tabs I have available are Statistics, Inspectors, AutoResponder and Composer. 

When I continue through the exception, I get several strange behaviors - the splash screen remains visible, the Tools options that use ShellExecute fail and the app must be forced to close.  I assumed these were all the result of an incomplete startup.

 

I appreciate your help on this.

Tommy

[EricLaw]

Ah, sorry, I hadn't considered that possibility. Here's a version that should ensure that the other tabs get loaded: http://ericlawrence.com/dl/Fiddler4ALPHASetup.exe

[Tommy Lenz]

OK, here it is.

Still errors on startup but continues with the KeyNotFound.

Here is the exception Ctrl+C text:

---------------------------
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 using the Help | Send Feedback menu.
The given key was not present in the dictionary.
Type: System.Collections.Generic.KeyNotFoundException
Source: Fiddler
   at Fiddler.WinINETConnectoids.GetDefaultConnectionGatewayInfo()
   at Fiddler.Proxy.RefreshUpstreamGatewayInformation()
   at Fiddler.Proxy.CollectConnectoidAndGatewayInfo()

Fiddler v4.4.4.2 (x64 AMD64) [.NET 4.0.30319.296 on Microsoft Windows NT 8.3.8601.65536]
---------------------------
OK  
---------------------------

 

This is followed immediately by a messagebox titled "Error" that reports "Failed to register Fiddler as the system proxy."

 

The Log tab text you requested is:

-= Fiddler Event Log =-

See http://fiddler2.com/r/?FiddlerLog for details.

15:05:11:0388 Fiddler Running...

15:05:11:0603 Assembly C:\Program Files (x86)\Fiddler2\Inspectors\Be.Windows.Forms.HexBox.dll did not specify a RequiredVersionAttribute. Aborting load of Inspectors.

Selecting Capture Traffic repeats the identical Error/Messagebox sequence that occurs during startup.

 

[EricLaw]

Thanks for your patience, Tommy.

 

Interestingly, this error message claims that you're running on "Windows NT 8.3.8601.65536". Windows 7 is "Windows NT 6.1" and no Windows version uses a build number of 8.3. Do you have any unusual software or utilities installed on your PC?

 

I'm pretty sure I've narrowed down the problem to a failing Windows API call. If you install this latest build: http://ericlawrence.com/DL/FIDDLER4ALPHASetup.exe the error code should be trapped in the Log.

 

In the QuickExec box immediately below the Web Sessions list, can you type about:connectoids hit Enter, and then tell me what you see on the Log tab?

 

thanks!

[Tommy Lenz]

Eric,

Sorry for the delay - worked behind a tight firewall this morning.  That is curious about NT build number... I can't duplicate that.  The Windows System Information tool and System.Envirnment.OSVersion report 6.1.7601 with SP1.   BTW, I previously told you I had two VPN connections.  You'll see in the log below that I removed one I no longer use and now have only one.

 

Here is the log you requested:

-= Fiddler Event Log =-
See http://fiddler2.com/r/?FiddlerLog for details.

13:13:11:4490 Fiddler Running...
13:13:11:4645 Assembly C:\Program Files (x86)\Fiddler2\Inspectors\Be.Windows.Forms.HexBox.dll did not specify a RequiredVersionAttribute. Aborting load of Inspectors.
13:13:11:4645 Fiddler was unable to get information about the proxy for 'DefaultLAN' [0x57].
 
13:13:11:4800 !WARNING: Failed to get proxy information for Connection 'DefaultLAN'.
13:13:11:4800 Fiddler was unable to get information about the proxy for 'EBRCC VPN' [0x57].
 
13:13:11:4955 !WARNING: Failed to get proxy information for Connection 'EBRCC VPN'.
13:13:11:4955 Fiddler was unable to get information about the proxy for 'BluetoothConnection' [0x57].
 
13:13:11:4955 !WARNING: Failed to get proxy information for Connection 'BluetoothConnection'.
13:13:11:4955 !WARNING: The DefaultLAN Gateway information could not be obtained.
13:17:05:8232 RAS reports 0 Connectoids

[Tommy Lenz]

Fixed it.

[Tommy Lenz]

Eric,

Doing a search of the hard drive, I noticed several logs called Fiddler.exe.0.dat, Fiddler.exe.1.dat, etc.  Apparently an application called Microsoft Application Verifier 4.1 (x64) has been logging fiddler (and only Fiddler) since 9/12/11.  Not sure how it got on my box or how Fiddler got added to it's "Image Name" box, but when I remove Fiddler from Application Verifier - all is well.  This is repeatable, i.e. add Fiddler back to Application Verifier and it errors again.

 

In the App Verify log files, there is a node:

  <avrf:logEntry Time="2013-05-02 : 13:38:43" LayerName="HighVersionLie" StopCode="0x2202" Severity="Information">
   <avrf:message>Called the GetVersionEx API.</avrf:message>
   <avrf:formatmessage>Returned 8.3 build number: 8601, service pack: 0.0, suite mask: 0x00000000, product type: (null).</avrf:formatmessage>
   <avrf:parameter1>0 - N/A</avrf:parameter1>
   <avrf:parameter2>0 - N/A</avrf:parameter2>
   <avrf:parameter3>0 - N/A</avrf:parameter3>
   <avrf:parameter4>0 - N/A</avrf:parameter4>
  </avrf:logEntry>

Notice the LayerName attribute is "HighVersionLie" and it returns the 8.3.0.8601 number.  Good call on the "unusual utilities" question.  I'm still not sure why the error only manifested itself recently.  I'm suspicious of IE10 update but, like I said before, it could be coincidental.

 

I did buy your book yesterday while I was trying to diagnose this issue.  Super good information.  I would strongly recommend it to anyone who uses Fiddler on a regular basis.

 

Thank you for your help and your excellent tool

Tommy Lenz

 

[EricLaw]

Wow, that's super-crazy! As far as I know, AppVerifier is only ever installed and operated manually. I'll have to ask some contacts at Microsoft about this.

 

The fact that this impacts the WinINET API call is a fascinating finding. My guess is that WinINET is performing a platform-check to determine whether it's running on Win7 or Win8 and it's confused by the result of the version-lie.

 

Thanks a ton for all of your work in narrowing this down.