抓包工具中，Fiddler 也算大名鼎鼎了。身材小巧，功能强大。设置支持 HTTPS 时，一般很顺滑，但有时，会各种报错。

Can't create the key of the subject ('<some guid>')
Failed to acquire a security provider from issuer's centificate

经实验，一般都是本地无法生成 DO_NOT_TRUST_FiddlerRoot 本地伪证书时造成，由于目录权限不对，导致无法创建或者无法覆盖。解决方法：只要删除 %APPDATA%\Microsoft\Crypto\RSA 让软件重新生成证书即可。

外：插件篇

Fiddler 作为一款杀手级应用，本身有各种各样的实用插件，当然平时比较少会用到。

Traffic Differ

The Differ tab allows you to compare two traffic profiles.

JavaScript Formatter

A simple tool for formatting JavaScript (47kb). Right-click on any JavaScript session and choose Make JavaScript Pretty, or use the Rules menu option to do this automatically for all downloaded scripts.

CertMaker for iOS and Android

iOS devices and Android devices may not work with the default HTTPS interception certificates used by Fiddler. To resolve this incompatibility, you may install a Certificate Generating plugin that generates interception certificates compatible with those platforms.

Syntax-Highlighting Add-Ons

This package contains the three most valuable extensions for Fiddler.
These add-ons display markup with syntax-highlighting:

The SyntaxView Inspector offers syntax-highlighting for HTML, JavaScript, CSS, XML and other web formats.
The RulesTab2 extension is a powerful way to edit your FiddlerScript Rules directly within Fiddler.
The FiddlerScript Editor is a standalone text editor that helps you edit rules for Fiddler. It offers syntax highlighting and a Class Explorer to help you author scripts.