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Unplanned
Last Updated: 22 Jun 2020 07:13 by Tony
Tony
Created on: 12 Jun 2020 15:09
Type: Bug Report
1
Failed to register Fiddler as the system proxy - after Fiddler update to 5.0.20202.18177

Hi,

I updated Fiddler to v5.0.20202.18177

Progress Telerik Fiddler Web Debugger

v5.0.20202.18177 for .NET 4.6.1
Built: mardi 14 avril 2020

64-bit AMD64, VM: 37,0mb, WS: 65,0mb
.NET 4.8 WinNT 10.0.18362.0

You've run Progress Telerik Fiddler: 17 times.

Running on: xxxx:8888
Listening to: All Adapters
Gateway: No Gateway

Copyright ©2003-2020 Progress Software Corporation. All rights reserved.and started to get error at launch

then i started to get error at launch : Failed to register Fiddler as the system proxy

I found a possible solution : change "WinHttp Web Proxy Auto-Discovery Service" startup to automatic

a reboot later, Fiddler worked fine 

but today, the error is back

i checked, the service is still in automatic startup

 

So i get a previous installer, and installed a previous version and the error is gone

Tried to update again, the error come back, rollbacked to previous version, working again

Progress Telerik Fiddler Web Debugger

v5.0.20182.28034 for .NET 4.6.1
Built: mercredi 27 juin 2018

64-bit AMD64, VM: 62,0mb, WS: 118,0mb
.NET 4.7.1 WinNT 10.0.18362.0

You've run Progress Telerik Fiddler: 18 times.

Running on: xxxx:8888
Listening to: All Adapters
Gateway: Auto-Config
	Offline/disabled

Copyright ©2003-2018 Telerik EAD. All rights reserved.

Didn't found any thread on the forum about this issue

9 comments
Tony
Posted on: 22 Jun 2020 07:13

Hi Eric,

Thank you for your help and replies, i'm glad if my feedback can help with this issue.

I will keep following the item as you recommend.

Thanks again

Regards

ADMIN
Eric R | Senior Technical Support Engineer
Posted on: 19 Jun 2020 19:54

Hi Tony,

After reviewing the proxy changes in the source, I do see some changes that might have caused this regression. As a result, I have logged this into our system. 

Until the fix has been implemented, I recommend using version 5.0.20182.28034. Additionally, we may require more information about the organizational proxy requirements.

As a token of gratitude for your feedback, I have increased the priority of this item by adding a vote on your behalf. I encourage following the item to receive future updates. 

Please let me know if you need any additional information. Thank you for your valuable feedback.

Regards,


Eric R | Senior Technical Support Engineer
Progress Telerik

Progress is here for your business, like always. Read more about the measures we are taking to ensure business continuity and help fight the COVID-19 pandemic.
Our thoughts here at Progress are with those affected by the outbreak.
Tony
Posted on: 19 Jun 2020 13:28

Hi Eric,

None of the 2 options suggested worked.

Version v5.0.20182.28034 is working perfectly, as-is, same system, same settings, no admin rights.

Something changed between the 2 versions in Fiddler.

Regards

ADMIN
Eric R | Senior Technical Support Engineer
Posted on: 18 Jun 2020 20:32

Hi Tony,

Unfortunately, this appears to be caused by the organization controlled proxy settings. My first recommendation is to double checking with the IT department and see if this version of Fiddler is approved for the environment. However, there are a couple of alternative options to try which I have listed below.

Option 1. It may be possible to change the proxy settings manually. This can be accomplished by using Tools -> WinINET Options -> LAN Settings -> Advanced. See the below screenshot for a visual reference. Can you confirm if changes stick after clicking ok? Run netsh winhttp show proxy form the command line to verify.

Option 2. It might help to open Fiddler as an Administrator. Can you confirm if you receive the same error as an Admin?

Please give the above a try and let me know the results. Thank you and I look forward to your reply.

Regards,


Eric R | Senior Technical Support Engineer
Progress Telerik

Progress is here for your business, like always. Read more about the measures we are taking to ensure business continuity and help fight the COVID-19 pandemic.
Our thoughts here at Progress are with those affected by the outbreak.
Tony
Posted on: 18 Jun 2020 15:04

Hi Eric,

Thank you for your suggestion.

I changed the Gateway configuration to Automatically Detect Proxy using WPAD

Unfortunately i still have the same issue, even after closing and restarted Fiddler

Please note with the previous working version, the setting is the default one : Use System Proxy (recommended)

Regards

ADMIN
Eric R | Senior Technical Support Engineer
Posted on: 18 Jun 2020 13:33

Hi Tony,

Thank you for providing the additional information. In reviewing the screenshots, I can see that the Gateway configuration is different after upgrade. Can you confirm if Fiddler works after upgrading by changing the Gateway configuration to Automatically Detect Proxy using WPAD as shown below screenshot?

I believe the reason why Fiddler was unable to Register as the System Proxy is because the System Proxy is managed by the organization. Changing the Gateway to Automatically Detect settings should resolve the issue. 

Please let me know if you need any additional information. Thank you and I look forward to your reply.

Regards,


Eric R | Senior Technical Support Engineer
Progress Telerik

Progress is here for your business, like always. Read more about the measures we are taking to ensure business continuity and help fight the COVID-19 pandemic.
Our thoughts here at Progress are with those affected by the outbreak.
Tony
Posted on: 16 Jun 2020 14:39

Previous post with Fiddler settings screenshots

Forgot the windows proxy settings, it does not change after Fiddler startup

Again, reinstalling previous version of Fiddler solve the issue, no uninstall, only install on existing version

Attached Files:
Tony
Posted on: 16 Jun 2020 14:35

Hi Nick,

Thanks for your reply.

I upgraded Fiddler again to provide requested additional information.

Here are the Fiddler logs after failed startup:

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

16:25:44:7597 Fiddler Running...
16:25:44:7597 !WARNING: The DefaultLAN Gateway information could not be obtained.
16:25:44:7597 !WARNING: The DefaultLAN Gateway information could not be obtained.
16:25:44:8175 Windows 8+ AppContainer isolation feature detected.

 

Attached Files:
ADMIN
Nick Iliev
Posted on: 16 Jun 2020 14:14

Hello Tony,

 

Many different reasons might cause the issue, so we will need some more information to investigate your case. If possible, please provide the following:

- Share screenshots of your Fiddler settings and the Fiddler logs (from the Log tab).

- Share screenshots of your Windows proxy settings before and after you open Fiddler.

Also, let us know if you are using a specific security tool or VPN program (for example, like CiscoVPN).

 

Regards,
Nick Iliev
Progress Telerik

Progress is here for your business, like always. Read more about the measures we are taking to ensure business continuity and help fight the COVID-19 pandemic.
Our thoughts here at Progress are with those affected by the outbreak.
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