When I open Fiddler Classic, the Firewall rules no longer work. For example, I have a rule blocking all outbound traffic from Google Chrome. When Fiddler is not opened, the rule works and I am unable to access the internet through Chrome, but once I open Fiddler, the Firewall rule stops working and I can browse the internet normally.

I believe this has something to do with Fiddler connecting me to a proxy which bypasses the Firewall. So I tried unchecking “Act as system proxy on startup” under Options → Connections, but this causes Fiddler not to record any traffic at all. I also tried selecting “No Proxy” under the Gateway tab, but this does not seem to have any effect.

How can I fix this issue? Do I have to configure the Firewall settings to apply to the proxy? I am using Windows 10.

I'm trying to add a function that enables me to programatically hide certain domains and retain such list as a BindPref.

However the function generates an unexpected error "Expected expression".

I've ran the function on jsFiddle.net and it works very well in their javascript engine, hence I suspect an issue with FiddlerScript.

class Handlers
{
[...]

static function OnPeekAtRequestHeaders(oSession: Session) {
	if(containsIgnoreDomain(oSession)) oSession["ui-hide"] = "yup";
}

static function ContainsIgnoreDomain(oSession: Session) {
        var ignoreDomains = [ "micosoft.com", "google.com", "googleapis.com", "gstatic.com", "gvt2.com", "gvt3.com"];
	
	const present = ignoreDomains.filter( domain => oSession.url.endsWith(domain) );  //   <<<<=== ERROR HERE 

	if(present.length > 0) return true;
	else return false;
}

[...]
}

Hi. In the new version of Fiddler everywhere, it is not possible to monitor traffic with an iPhone. Fiddler does not connect to the iphone. It was conveniently used in the earlier version.
Would you please support.

I have a job which executes few webservices. When executed manually I keep the Fiddler app on and it captures the traffic.

But if I am scheduling the aforesaid job via Jenkins then is it feasible to capture the traffic? If yes then how?

I have tested using online unpkg https://nuget.telerik.com/v3/index.json and local file dir, Neither can be installed. The screenshot is as follows. Please help troubleshoot the problem.

So I have a https proxy that I know works. I use it in Firefox all the time and did a sanity check just before and after setting it up in Fiddler Classic to ensure it works in Firefox which it does. 

Unfortunately it doesn't work with Fiddler Classic and my mind is boggled. The docs for Fiddler Classic seem rather limited as I've been digging through them in frustration. Murphy's law in full effect I guess.

So here's what I've done:

1. I have local fiddler proxy listen on 8888 in connection tab.

2.. Act as system proxy on startup is checked

3. In the gateway tab I have manual proxy entered in the following format: username:password@remote-proxy-ip:32222

4. When I click on "Show Current Gateway Info" it tells me HTTP / HTTPS / FTP Gateway specified was unreachable and is being ignored" I don't care about FTP but I do care about HTTP / HTTPS. 

5. When I try to collect to the local fiddler proxy, the connection itself works fine but it's not chaining into the remote proxy; the remote proxy is being ignored as stated in 4 because I see my normal external ip instead of my remote proxy ip for the ip address.

Please find the attached picture below