A course is valid for a year by default, because most licences are also valid for a year.. You can extend the preservability of a course once it has been created, even if there are learners subscribed.
Where can I edit the course preservability?
Go to the tab Courses and choose Settings at a Course.
At the tab Settings you will find the preservability properties that you can change. After Updating, the settings are adjusted for all learners that are still active in the course, except for the learners that have a specific end date. You can check this at the tab Learners.
The learners that have the status Expired, will remain expired after the preservability settings have been changed. You can activate them by selecting them and then click Activate. Note that if a learner still has access to an active course after a year, a new license will be deducted from your balance.