I encountered a dialogue eavesdrop bug today during multiplayer. This occurred on the beach area just after the Nautilus tutorial. After I eavesdropped on the other player's conversation, the game seemed to think that one of us was always stuck in mid-conversation even after that conversation ended. We tried entering battles or starting new conversations with NPC's but nothing seemed to break the "you are in mid-dialogue" bug. This consequently made it impossible to save.