If the Rucksack contains higher level taxa then the expansion of these might have an effect as the way this is done has changed is done  has changed.  Occasionally taxa are removed from the Dictionary and this could have an impact. Changes in Nameserver may also have an  effect. If your Rucksack contains higher level taxa then this would be the most likely reason for a problem.  If you can attach a Rucksack which yiu have doubts about I will take a look.