Hi Max,
Yahoo recently changed their weather service API, so that the current demo house configuration will not work anymore.
You have to modify the demo settings according to this post (maybe not quite easy for a “newbie”):
Or you have to choose another weather provider (but this also has to be combined with some config changes).
Third solution: Delete all Yahoo entries from the demo files. Or simply ignore the error, since it’s just a Demo. 
Regards,
Stefan