With almost no examinations taking place, teachers graded pupils in key subjects and the marks were then moderated by examination boards. To the dismay of pupils and parents, 75,000 young people saw their grades revised down.
Similar issues could begin to emerge on Thursday when students in England, Wales and Northern Ireland receive their A-level results, on which many university places are based.
“All downgraded awards will be withdrawn,” said Scotland’s education minister John Swinney.
“In exceptional times, truly difficult decisions have to be made. It is deeply regrettable that we got this wrong and I am sorry for that.”