I saw a thread related to this that was marked as CNR so I hope this isn't redundant, but I experienced the same issue as that user. Pregame my opponent revealed a Chancellor of the Annex, on my turn played a land, passed and then at the end of my opponents turn I cast a Once Upon a time paying the alternate cost while I had a Verdant Catacombs on the battlefield. The Chancellor trigger when on the stack and I was unable to sacrifice my Catacombs to get a land to pay for it and so the Once Upon a Time was countered.
