Chris Kirk has kindly provided a Q&A PDF which summarises a number of problems that have been raised and answered in the comments on the tutorial page. If you are having problems, download it and see if it helps.
The views expressed in these comments are not the views of the publisher. However, we believe in the rights of others to express their legitimate views and concerns. Any legitimate complaint emailed to firstname.lastname@example.org will be seriously considered and the post reviewed as desirable and necessary.