If your course is not in weekly format, you may have noticed that the button for dragging section blocks has disappeared. We’re working on a long-term solution to this problem, but for the time being you can switch your course into weekly format, move your blocks, and then switch back into your format of choice.
1) From the course main page, go to your settings block > course administration > edit settings.
2) Under formats, click weekly.
3) Arrange your course.
4) Return to the edit settings page and return to your normal format.