Same problem for me. The iOS / watchOS app runs, so far ok, but when trying to arrive I ge the same error message.

oh this autocorrection: "trying to archive" !!!

Fine, but what does it mean in implementation terms if an activity qualifies as "walking" or "cycling"? The documentation gives you just a wording, but the sensor data and their development in time frames must be very different. How do the respective data models for different activities look like?