Hi Joe,
Doh! Thanks for letting me know surprised there haven't been a lot of reports of this. I will fix this in the packages asap. It was a last minute decision to make a new set of skins and move the old ones into the extra-skins download. But I forgot about this web.config setting:
<add key="DefaultInitialSkin" value="artisteer31-green" />
That skin no longer exists so in new installs its setting it to an invalid skin when it creates the site.
I'm going to update the packages to correct this right now.
Thanks,
Joe