How to use Fiddler in C# with a proxy?

I've been using Fiddler in C#.

So far I'm able to intercept requests. However, I need to set a proxy. I did so, the proxy is set.

In Proxy Settings Windows' form, I have for HTTP and Secure: 127.0.0.1 for Proxy address to use and for the Port, 8888.

This is the same that is done when I use Fiddler application directly.

However, when I set it through my C# code, instead of using Fiddler, I can't navigate. My pages give me the message:

Your connection is not secure

What more do I need to do? What Fiddler do that I'm missing to correctly set a proxy?

Solution

Usually if it cant make a secure connection, you need to trust Fiddler's root certificate on your development PC. If you are using Firefox you will have to do an additional step to trust the certificate inside FF.