The following styles in the styles demo display a general error when visiting stating the template path could not be found:

http://www.phpbb.com/styles/demo/3.0/?style_id=59
http://www.phpbb.com/styles/demo/3.0/?style_id=11
http://www.phpbb.com/styles/demo/3.0/?style_id=27
http://www.phpbb.com/styles/demo/3.0/?style_id=85
http://www.phpbb.com/styles/demo/3.0/?style_id=95
http://www.phpbb.com/styles/demo/3.0/?style_id=21