UPDATE 1:
After to tinkering I realize that if I create a new course I can manually add it to an order, something I was unable to do. It looks like existing orders were passed on but the new version of LP cannot access the database for pre-upgrade courses, only new ones.
UPDATE 2:
I tried importing a backup of my courses and am now able to add them to orders. I’m not a DBA but I have to assuming that the database was not updated (upgraded??? maybe but cant say for certain). Hope this info helps in some way.
Same problem here. I tried disabling all the other plugins but with no success. I then disabled and re-enabled the learnpress plugin and the notification disappeared. Not sure if the database was really updated because I now have the problem of not being able to create new orders or add to existing orders.