If you were looking forward to seeing The Weeknd have a singsong before Rihanna on the European leg of her Anti tour then we advise you sit down and do your breathing exercises because the dream is over.
According to a statement from Live Nation (as quoted by Billboard) it's all to do with "some unforeseen changes with upcoming projects", which is concert promoter speak for "something more important's come along".
Mind you, a source with connections at Billboard has said that basically "[Abel] has hit a stride on his new album and decided not to interrupt the process".
So there we have it. A space for Carly Rae Jepsen to fill.