My rogue equipped the Helm of Lightbringer after acquiring it from the dragon. Didn't require attunement. During combat, she tried to use the item to cast Shine on a Brood. Spell did not fire, and the game essentially stopped. I could still move the camera, but the character option menu disappeared so I couldn't perform any actions or end turn. All menu options were disabled except Journal, so I couldn't reload. Had to end program and restart the game completely. Definitely a bug.
I'm not laughing AT you, I'm laughing WITH you. You're just not laughing.