I just saw this message when trying to complete “Who Dares,” and I found it addressed in another thread, but creating some troubleshooting instructions in a standalone post for anyone else who might encounter it (and it might be helpful for Wahoo to update the message with instructions on how to access these workouts).
This error seems to happen for previously scheduled or newly recommended workouts that are being updated, but I was able to access the workout by opening it from scratch starting over from the beginning with the Library menu and then searching or browsing to the workout.