FiddlerCore is blocking all redirects

[Andy Spears]

I am using Chromium to embed an web browser in a winforms app.  I insert custom JavaScript into the pages to automatically redirect the user to a login page if a certain HTML condition exists.  All this works as expected so I then added FiddlerCore with the hopes of modifying certain HTTP requests.  The problem is as long as FiddlerCore is running, page redirects initiated via JavaScript calls are canceled (see attached image).  I have very minimal code running, so I'm guessing I'm missing a configuration setting somewhere.  Any help would be greatly appreciated.  Below is the FiddlerCore code that I'm using:

 

public void Start()
{
    if (!IsStarted)
    {
        IsStarted = true;

        Fiddler.FiddlerApplication.BeforeRequest += FiddlerApplication_BeforeRequest;
        Fiddler.FiddlerApplication.BeforeResponse += FiddlerApplication_BeforeResponse;

        // For forward-compatibility with updated FiddlerCore libraries, it is strongly recommended that you
        // start with the DEFAULT options and manually disable specific unwanted options.
        FiddlerCoreStartupFlags oFCSF = FiddlerCoreStartupFlags.Default;

        // NOTE: In the next line, you can pass 0 for the port (instead of 8877) to have FiddlerCore auto-select an available port
        int iPort = 8877;
        Fiddler.FiddlerApplication.Startup(iPort, oFCSF);

        FiddlerApplication.Log.LogFormat("Created endpoint listening on port {0}", iPort);

    }
}

public void Stop()
{
    if (IsStarted)
    {
        IsStarted = false;
        Fiddler.FiddlerApplication.Shutdown();
        Fiddler.FiddlerApplication.BeforeRequest -= FiddlerApplication_BeforeRequest;
        Fiddler.FiddlerApplication.BeforeResponse -= FiddlerApplication_BeforeResponse;
    }
}

void FiddlerApplication_BeforeRequest(Fiddler.Session oSession)
{
         Console.WriteLine(oSession.fullUrl);
}

void FiddlerApplication_BeforeResponse(Fiddler.Session oSession)
{
}

[Eric Lawrence]

Hi, Andy--

You should hook up the OnNotification and OnLogString handlers as shown in the demo Program.cs. After you do so, I expect you'll find that there are error messages complaining that FiddlerCore isn't able to generate certificates for HTTPS interception because the certificate generator can't be found, or similar messages indicating that you haven't yet configured the system to trust FiddlerCore's root certificate (since I don't see any code that does that below)

Regards,
Eric Lawrence
Telerik

[Andy]

Thanks, that helped me get the information that I needed.