Well, I can no longer see the actual puzzle on this, nor the tutorial elements: http://nova.eternadev.org/web/puzzle/3388965/
When I remove the line “#PRE-HideUI energy, togglebar, undo, redo, swap;” and resave it, then reload the puzzle, it works again. I don’t have time to check which or if any of these (ie it’s the instruction itself) cause the issue, but I can tomorrow and report my findings.
Edit: It is in fact the energy element that’s causing the issue.