Sometime within the last day, the functionality of those parts of the interactive lessons in which user "rate it" data is stored and retrieved have started to not function properly. For example, in the "Hear It! Say It!" exercises, one may listen and record the first item, but then the "Rate It" functionality is not working (i.e. clicking on any of the "Rate It" buttons does nothing). Thus, the user cannot proceed to the next item, rendering the exercise unusable from that point on.
Similar problems are preventing "Write It", "Know It", and "Quiz" items from properly functioning. Note additionally that no value is being displayed for "% Complete" on any item. All these symptoms suggest that read/write access to the back-end data-stores has broken down.
Thanks for attending to this!
(BTW, I'm using the Japanese lessons, but am supposing that this may not be a language-specific issue.)