Thats right, he doesn't find the node.
The XML looks like this:
< ?xml version="1.0"?>
< configuration xmlns="http://schemas.microsoft.com/.NetConfiguration/v2.0">
< appsettings>
< add key="ipAdresseWebServer" value="XXX.XXX.XXX.XXX:XX" />
< /appsettings>
< /configuration>
So whats wrong?