Belfast's showpiece Waterfront Hall is to shut for three months while €1.5 million of urgent repairs are carried out.
The council-owned venue's management committee is threatening legal action after discovering the main stage needs to be replaced.
Christopher Stalford, chairman of the Waterfront Board, said it was " absolutely disastrous" news.
"The stage and pulleys were sold to us on the basis they would last 30 years yet the Waterfront is only nine years old."
Mr Stalford, a Democratic Unionist councillor, said the leverage system had not worked properly since the arena opened. Staff have forced the equipment to work, but the situation has now worsened, he revealed.
"We can't guarantee the stage can be moved up and down, it could get stuck in mid-air and that has an impact on our capacity to put on a show.
"The hall will have to be closed for 12 weeks. We're just trying to find a time when it's least used in order to minimise disruption.
"We are undertaking legal action against the company that installed the system," Mr Stalford added. "This is an enormous cost to the ratepayer and the committee as a whole are shocked."