In case you are talking about the WaniKani Double-Check script:
This is because the Double-Check script only uses answerChecker.evaluate(). The new functionality is in enhanceAnswerChecker({evaluate: answerChecker.evaluate}).evaluate(). I have already posted a fix for the Double-Check script. @est_fills_cando has integrated my fix into their fork, which includes even more bugfixes and features.
@rfindley, if you have time, could you update the code on GreasyFork to include @est_fills_cando’s changes? The vocab audio will break with the current version as soon as the announced audio player changes go live on the main site.