전화위복
轉禍爲福 · turn misfortune into fortune
A setback that turns out to be a blessing.
When to useA cancelled plan that led to something better.
Examples
그 실패가 전화위복이 되어 새 길을 찾았다.
That failure turned into a blessing — I found a new path.
Korean life dictionary
22 short guides to words and manners