Thanks! I have found another way. There’s a feedback button on the side pane. =)
All the docs.mendix.com can get edited by all of us, but unfortunately not the lectures. And posting the typo on this forum will probably not get the editor’s attention. Allthough this is of course no biggy, you best create a ticket for this at support.mendix.com.
Are you sure you have named the object NewCourse instead of Course in step 7.7.1.2?
It is not clearly stated that the object has to be renamed to NewCourse in 7.7.1.2 (at least, as far as I'm concerned). It would make sense I believe, but the thing that puts it off again, is the example that is being shown in 7.7.5.3: completing the microflow.
This inconsistency had me doubting for a moment too, in the end still not sure whether $Course or $NewCourse is the correct use.