Fiora Passive says "Spell not found" and Duelist's dance doesn't exist

I am not sure how the bug came to be, but when I started a game Fiora's passive "Duelist's Dance" said only "spell not found". I played the whole game without her passive being on in a ranked match, not sure if you can check my match history - TelevisedWheat on september 29th 2018 around 10:30 am. I have no idea why it happens but the whole game her passive just said "spell not found"

Thanks