I just installed it myself and it does work! Thanks to jlunman.
jlunman wrote:Good news - I have a fix!
The problem is with a Microsoft-hosted web server, not Netflix. Media Center is trying to contact https://ehome.vo.msecnd.net/, which is currently responding with a "504 - Gateway Timeout" error.
The good news is that the failing server is not actually responsible for the search itself. All it does is provide Media Center with a bit of meta information (the "search taxonomy") about what its Internet TV search providers are, and what sort of filters they support, etc. Most of those were for the old Internet TV channels that are officially discontinued anyway. All that really remains is Netflix.
It turns out you can override the search taxonomy URL with a registry entry. So I created a simple Windows Service that acts as a local substitute for Microsoft's broken server, and serves up a dirt-simple SearchTaxonomy document with the minimum necessary information to allow Windows Media Center to initialize the Netflix search.
You can download it here. Extract the files and run Install.bat, with the "Run As Administrator" command. Once installed, the Netflix search should just work.
The code is hosted on GitHub, if you're curious about the technical details.