Please make sure that you have updated version of vibe course module plugin (126.96.36.199) .
Check if you have put some value in the number of seats and max course duration in course settings .
Please just got your free courses and make sure you just provide a value in seats field and max course duration field and save settings of your courses and then check the course again.
Thanks for the very speedy response. I have version 1.9.8. I've entered my API key for auto updates after receiving your message, but is there a way to force the update? I don't see Student Seats in the course setup, and am assuming it's because I need the minor update.