Rule reminder
'Avere paura' = to be afraid (literally: to have fear). To say you're afraid OF something: 'avere paura di + [thing]'. Example: 'Ho paura dei ragni' = I'm afraid of spiders. 'Paura' is feminine.
Completa: 'Il film era così brutto che _____ tutti paura.' (The film was so scary that they were all afraid.)