This issue is frequent in Wishlist
When you create an assessment, a new step gets added to your course, that will be available to your students. When they finish the course, they will have a button to take the assessment, which will then take them to the first part of the assessment journey, where they can start the test.
However, if you are having an issue causing the page to not load when a student clicks the button to take the assessment or to start it, you will need to follow these steps:
1. In your wp-admin dashboard, go to eLearn Commerce -> Settings.
2. Select Assessments under Course Page.
3. Uncheck the Enable Protection checkbox.
That will solve the issue! If you still experience it, please open a Support Ticket.