When joining the Duel Links ranked, only the cards released in Duel Links are allowed. This is why you got invalid deck because some of the cards in your deck are not released in Duel Links. This is probably one of those synchro monsters.
When joining the Duel Links ranked, only the cards released in Duel Links are allowed. This is why you got invalid deck because some of the cards in your deck are not released in Duel Links. This is probably one of those synchro monsters.