Take your pick:
https://www.businessinsider.com/mcdonalds-franchisees-say-all-day-breakfast-is-a-nightmare-2015-10
https://www.theatlantic.com/business/archive/2015/10/all-day-breakfast-anticipation-luxury/409552/
https://www.eater.com/2015/10/16/9553041/mcdonalds-all-day-breakfast-disaster-franchisees-upset
https://nypost.com/2015/10/15/mcdonalds-all-day-breakfast-has-been-a-disaster/
https://www.inc.com/associated-press/mcdonalds-all-day-breakfast-not-enough-drive-sales-above-market-expectations.html
It failed. The cost to reward ratio was out of whack. Americans who want breakfast after breakfast don’t go to McD.
News articles? No thanks. I want to see their actual documents.