In the midst of his European tour, Usher has reportedly fallen ill with a respiratory infection — forcing him to cancel several shows leaving fans disappointed.

After canceling his Berlin O2 Arena show on Wednesday, he promised to make it up to fans the next night. Sadly, he was unable to do so. According to CNN, Usher lip-synched his first couple of songs and could barely dance. German fans began to boo and complain about Usher’s performance. Overcome by his own illness and the audience’s cold response, he hung his head for a minute before exiting the stage. The show ended as fans were told he was indeed too sick to carry on.

Usher has been advised by doctors to cancel his upcoming dates so he may fully recover. “I deeply regret having to reschedule the shows… I am truly sorry for any inconvenience I have caused my fans. My fans are the best in the world and I am looking forward to getting better so that I can give them the show they deserve,” he said.