disillusioning

ˌdɪsɪˈluːʒ(ə)n

verb

cause (someone) to realize that a belief they hold is false.

if they think we have a magic formula to solve the problem, don’t disillusion them

disabuse,undeceive,enlighten,set straight,open someone’s eyes,disenchant,shatter someone’s illusions,disappoint,make sadder and wiser,throw cold water on