You can copy course content such as assignments, modules, pages, and discussions from previous Canvas courses into existing courses. You only have access to copy content from courses in which you are enrolled as a user with instructor permissions.
Courses that are past their Term Dates or manually set Course Participation Dates are still visible to all instructors and participants, but prevent participation or modification after that date. Courses from previous terms are organized and accessible under the "All Courses" list from the Global Navigation menu.
If you are the self-hosted Open source Canvas LMS administrator, you would get this error message from your end users: This website is under heavy load (queue full). We need to think about why this happened? Here is the clue and solution you would try.