New I'ble single-step URLs are broken for steps 10 and later Answered
As Jamalam posted this morning, a new bug was introduced with the overnight feature rollout. For published Instructables, the individual steps now have human-readable URLs of the form "https://www.instructables.com/<instructable-title>/step##/<step-title>/" (e.g., "https://www.instructables.com/id/Modified_Crib_for_Parent_with_Disability/step15/Attach-the-End-panel-Moulding/"). This is really nice.
Unfortunately, the server-side code which generates these URLs is buggy. For two-digit steps (step10 and higher), the URL does not resolve correctly, reverting back to the intro step. You'll see this if you follow the link above.