App Config’s root element should be namespace-less
The root element for Application config file is <configuration>
<?xml version="1.0" encoding="utf-8" ?>
<configuration >
</configuration>
The application config file is shared with CLR and Windows SxS.
SxS dictates that the root element is <configuration>, and it should be without namespace. If the application config file does not follow the rule, SxS will refuse to start the process.
