Error message in training course "Becoming an Outsystems Business Analyst", at lesson "Drill down user stories" of the "Storytelling" section.

The error message says: "Something went wrong on saving the progress".

The "Storytelling" section shares content with another course (previous mini-course with the same name "Storytelling", that I started a long time ago, so in my present training the first 3 lessons of the "Storytelling" section appeared checked as done. I check now the course materials and I remembered my previous training, When I finished the forth lesson "Drill down user stories", it show the error message, and if I click another lesson the page doesn't respond.

So, I click the buttons "previous lesson" and "next lesson", but then any of those clicks, refresh the page showing the same message error, but now both buttons are gone, they dissapear. 

So I can't continue with my training.

Could you help me, please? Thanks!