The most likely reason for this error message is that you are not logged into the CALI website. All CALI Lessons, LessonLinks and Autopublished lessons can only be viewed by those that are logged in. If you do not yet have a CALI username and password, please view the FAQ on how to obtain those.
At the top of the webpage is the drop down to log in. After logging into the CALI website hit refresh. If that does not work, close the page and refollow the link you were given. Do not try to search for the lesson by title, as the link may be to an Autopublished lesson or a LessonLink. Those require access by a specific URL in order for your performance to be recorded.