"What was the matter with you yesterday?"
I agree to, it has been acceptable in every lesson so far that the subject (你 in this case) can have the day (昨天 in this case) when the event occurred on either side.
Drives you nuts this sort of thing in this course and just confuses your view of everything that has been taught. But then you wrote this a year ago and nothing has changed.
I'm tired of the inconsistency of not accepting variations on subject-adverb of time expressions. There is no way to predict what Duolingo will accept in these translations. 你昨天有什么事情？and 昨天你有什么事情？are absolutely equivalent. Both are correct, but the second is not accepted in this exercise. In other exercises, only an answer with 昨天 coming before the pronoun will be accepted. There is no way to predict which will be marked correct.
I totally agree. And it is bad for Duolingo. Why would you pay for a course when there is this constant irritation which is counter-educational.