Answer:
Tragic flaw
Step-by-step explanation:
The error or weakness could be the lack of self-knowledge, lack of judgment or the pride of the hero.
The tragic flaw is used with moral purposes to encourage the audience to improve their characters. The objective of the tragic hero is that the audience could identify with it. And by doing this the readers and audience could learn a moral lesson to not do the same in the future.
I hope this answer helps you.