Tutor LMS 404 error help

Hello,

Please could you help, we have 2 issues related to the quiz.

1 – When the student clicks on the Quiz tab in the Course home page it opens a new page with a 404 error showing or a page saying please purchase this course.
It is not happening on all the courses only on some, we are not sure why it does that.

2- When the student is inside the quiz and clicks the start quiz button it doesn’t work nothing happens. The solution seems to be that they click previous page or go away from the page and then come back and try and then it works but there is no start button it goes straight to the quiz.

Please can you help.

Thanks