Last night we deployed a new edition of the Karel course with significant improvements. Your students now have on-demand access to hints throughout the course, which much better reflects the needs of 21st century learners.
You can UNLOCK LEVELS for your students so they do not have to redo work they already did.
We already figured out how to do course updates in a more gentle way in the future, so you should not see any more course resets.
(on behalf of the NCLab Team)