.NET requests refused, after uninstalling fiddler

0 Answers 189 Views
Top achievements
Rank 1
Sebastian asked on 27 Jul 2021, 01:28 PM


I recently installed fiddler to reverse engineer an android app. How that I'm finished with my research I uninstalled fiddler. However it seems like that fiddler messed with my windows settings. I can no longer send a http request using .NET. When running the request via Postman or simply my webbrowser the request reaches my webserver and I get the answer.

This is the code I use to perform the request, which results in 'No connection could be made because the target machine actively refused it. ('.

So I was wondering, where this port was coming from, because I specified 5004 but it ended up to be 8888. I checked my windows proxy settings.

I also tried clearing the IWinNet Cache using fiddler. No effect.

Then I discovered that when running fiddler again, my requests goes through. I also noticed that the Capture Traffic options has no effect. No matter if I monitor the traffic or not, my request is shown in fiddler.

I don't know what to do, and really hate the fact that I always have to run a proxy in order to work!


Thanks in advance!


Nick Iliev
Telerik team
commented on 28 Jul 2021, 06:09 AM

Hello Sebastian,


The .NET applications are usually using an additional configuration so that their traffic could be captured by the Fiddler proxy. Check this article and see if your .NET application has a similar configuration setup (and if so reset it to its defaults).

No answers yet. Maybe you can help?

Asked by
Top achievements
Rank 1
Share this question