Preview performances of I Can't Sing!, a spoof of the British reality Tv series which has been backed by Cowell, were postponed twice due to technical problems and the first show was marred by long delays when it was finally unveiled to the public in London earlier this month (Mar14).
The West End musical is still facing technical issues two weeks later. The second act of Monday's show was cancelled after a major electrical fault at the London Palladium theatre caused a 45-minute delay.
Sean Foley, the show's director, came onstage to announce the problem and offered guests refunds or exchanges for an alternative night.
The show, starring Downton Abbey actor Nigel Harman, will officially open on 26 March (14).