The Radiohead rocker was due to hit the stage with his side-project at the Malta Festival in Poland, but the show was called off just hours beforehand.
A statement from organisers put the cancellation down to safety concerns. It reads, "We are sorry to inform that due to technical reasons related to the safety of the event, (the) concert of Atoms For Peace (sic) has been cancelled. The information on the refund of the tickets will be available on Monday, 22nd July."
Yorke added in a post on Twitter.com, "Sorry due to technical reasons - safety of the event... (the) show in Poland (is) cancelled."
No more details were available as Wenn went to press.