Demi Lovato announced that she was forced to cancel her concert, as part of her current tour due to ongoing health issues. "Rosemont, today I woke up and had absolutely no voice," the singer's message, posted to her tour's Instagram page, read. "I'm so sorry, but it breaks my heart to tell you I have to reschedule the show." The Cool for the Summer singer added, "Tickets will be honoured for a new date as soon as it's announced." Demi also shared her frustration with having to take some time away from the stage and her fans. "This is the absolute last thing I want to do," she wrote. "I'm having so much fun with you all and I can't wait to see you again. I appreciate your understanding. I love you all." Back in September, Demi expressed her frustrations with her ongoing health struggles. While Demi might be having to take a pause from tour life, she's certainly made every moment count. She invited Ashlee Simpson to join her onstage during her stop in Los Angeles, and they performed Ashlee's 2004 hit Lala in front of the audience.