Found another one:
In Dutch, it's unclear whether it's the second most common action among your own cards or the second most common action among all players' cards (for example, you'd get 3VP per village if you have the second most villages of all players).
Secondly, the final sentence in Dutch reads "If it's a tie, count all relevant cards". One action you have seven copies of and three actions you have five copies of? Get forty-five points!
EDIT: Two more.
In the Adventures rulebook, it says "Reserve cards are discarded during Clean-up normally on the turn they are called.", which is the only sentence that explains what to do when you call reserve cards on another player's turn. In Dutch, it says "Leg opgeroepen reservekaarten in de opschoonfase zoals gebruikelijk af.", which doesn't.
Also, the phrase 'This stays in play.' has been omitted from the Dutch Champion, although it's sort of implicit.