since 12.0.10 - there's no dummy sitebuilder included - that's why I think it fails, so for testing 12.0.10: install 12.0.9 and then upgrade to 12.0.11.
since release notes for plesk 12 is removed from plesk website - http://goo.gl/ShvIn3 you can find them it from google cache :P
log of...