You are looking at a very old, but free version of the course.
If you are interesed the most recent version, check it out
on the Perl Maven site.
When you find a problem it is not always the problem in the application you are testing.
If it was a human who did the work we would call it a "user error" but in our case the
user is a program itself. As the developer of the application can make errors the
person who writes the tests can also make errors.
If you are interested in on-site trainings by the author, please
contact me directly.