When you get error message as below with your php site
HTTP Error 404.11 - Not Found
The request filtering module is configured to deny a request that contains a double escape sequence.
You can add the code below to your web.config file in root folder, if there is no web.config file, you can create a new one.
<configuration>
<system.webServer>
<security>
<requestFiltering allowDoubleEscaping="true">
</requestFiltering>
</security>
</system.webServer>
</configuration>
Then the error would be fixed.
Article ID: 321, Created: January 22, 2013 at 1:01 AM, Modified: January 22, 2013 at 1:01 AM