1. Technical problem: Due to technical failure, the course cannot be accessed. Jianxun Education should provide corresponding solutions, fix technical problems or provide refunds.
2. Content update: the course has been updated or replaced, and the purchased version of the course is no longer available. In this case, you can contact Jianxun Education Customer Service and ask how to get an updated course.
3. Copyright issue: The purchased courses were removed from the shelves due to copyright issues, and the license agreement for training education has expired.