Yesterday Robert Lepage, the renowned actor and director, admitted that his reinterpretation of Shakespeare's Hamlet would not see one performance.
Elsinore, starring Mr Lepage himself, was to be the theatrical showpiece of the festival's first week, but the complicated technical equipment on which it relied broke down as it was due to open on Monday.
Mr Lepage said the problem had proved impossible to fix and that the show, due to run for five nights, had been cancelled.
The news will be a blow to the 3,000 people who had bought tickets costing between pounds 6 and pounds 20 to see what was described as "a remarkable synthesis of dazzling theatre technology and cinematic convention".
Mr Lepage explained at a press conference: "There was a huge piece of machinery that revolved and picked up huge pieces of sets. It depended on four motors to pick up the pieces, but one didn't respond."
Despite technicians working round the clock, it proved impossible to mend, and the only available replacement part was in Canada. Mr Lepage was, he admitted, extremely embarrassed and conceded that such heavy reliance on technology may have been risky.
Everything had gone smoothly during rehearsals and in the six months that the show, by the Ex-Machina Company of Canada, had been touring abroad.
It is the first time in living memory that the festival has lost such a high-profile show in such a way, and the cost to it is likely to be close to pounds 100,000, but its director, Brian McMaster, said that the festival had an insurance policy to cover such emergencies. The Bank of Scotland, which sponsored the show, had been "very supportive".
Mr McMaster said his staff would tell as many people as possible that the show would not be running. Tourist information offices in the city had been informed and credit card bookings would be automatically refunded.
The Ex-Machina Company was said to be devastated after having worked furiously to prepare the show for Edinburgh. It is due to tour Nottingham, Newcastle and Glasgow later this year and is also booked to appear at the National Theatre in London.