In the Scheduler, when I add a session to a time slot for any room, the session moves to the time slot and says "Updating..." and then hangs. You can continue to add sessions to time slots, but they all do the same. Reload the Scheduler and none of the sessions are added to the time slots. The issue appears to be in cod_schedule_field_collection_item_add(). This method assumes that the $entity_id passed to it is a nid. In this particular case, however, the $entity_id is an array with a single nid in it. Then when entity_load() is called, $entity_id is added to an array. The array within the array results in entity_load returning nothing. Not sure if this has been fixed in later beta releases, but also didn't see this reported anywhere else, at least not for this reason. I looked at Beta12 (granted without installing/updating the current install), and it appears to be structured the same. A simple fix would be to check if the $entity_id is an array or int before making the entity_load() call.