Internet Explorer 11包含一种名为AppContainer的新隔离技术，该技术由浏览器的增强保护模式功能使用。 EPM / AppContainer网络限制通过阻止Internet区域中的内容连接到本地网络或本地PC来帮助减轻对计算机的攻击。

您遇到的问题当区域设置使您的本地PC内容被视为 Internet区域时，会出现此问题。如果您要使用机器名称（例如 http：// mypc 或 http：// localhost ）内容将加载到 Intranet区域，因此超出保护模式，因此在AppContainer之外。

同样的功能阻止IE11使用Fiddler你的情景;您可以在此处了解有关此问题的更多信息：
http://fiddler2.com/blog/blog/2013/08/02/fiddler-and-internet-explorer-11-on-windows-8-1

要解决此问题，请使用Fiddler工具栏左侧的 Win8配置工具（或从 http://blogs.msdn.com/b/ fiddler / archive / 2011/12/10 / fiddler-windows-8-apps-enable-loopback-network-isolation-exemption.aspx ）

I'm using the XIP.IO wildcard domain to access a website running on a local IIS server.

Today, IE 11 stopped accessing the site, whilst Chrome and Firefox continued to have access. It even works on remote machines, so I know it's related to my local IE.

I've checked there are no proxy settings, reset IIS, reset IE 11, event reinstalled IE 11 - all to no avail. I'm running on Windows 8.1 preview.

This has worked for months without issue. I can't even think of any software that I recently installed that would cause this issue.

As a point of interest, when I fire up Fiddler, IE reports that the "Proxy isn't responding". It's almost as if it can't resolve local IP addresses or something.

Any pointers would be appreciated!

Internet Explorer 11 includes a new isolation technology called AppContainer which is used by the Enhanced Protected Mode feature of the browser. EPM/AppContainer network restrictions help mitigate attacks against the computer by preventing content in the Internet Zone from connecting to your local network or your local PC.

The problem you're encountering occurs when the zone settings are such that your Local PC's content is treated as Internet Zone. If you were to use the machine name (e.g. http://mypc or http://localhost) the content would load in the Intranet Zone and thus outside of Protected Mode and thus outside of the AppContainer.

The same feature prevents IE11 from using Fiddler in your scenario; you can learn more about this issue here: http://fiddler2.com/blog/blog/2013/08/02/fiddler-and-internet-explorer-11-on-windows-8-1

To resolve this issue, use the Win8 Config tool at the left of Fiddler's toolbar (or download the standalone EnableLoopback tool from http://blogs.msdn.com/b/fiddler/archive/2011/12/10/fiddler-windows-8-apps-enable-loopback-network-isolation-exemption.aspx)