“We thank the events team at the venue for their swift action and professional response to the medical emergency which was unrelated.
“The member of staff is recovering well.”
Liverpool had hired the city’s cathedral, the biggest in Britain, for the event, which saw the club’s crest projected high on to the chapel windows and the hall bathed in red light.
Bands had been booked to play at the party and one set ended early due to the shutdown.
The party had been organised as a thank you for the work of non-footballing staff during a year which has ended with Arne Slot’s team top of both the Premier League and Champions League tables.
Slot and his players were not thought to have been present at the gathering, having earlier been at Alder Hey Children’s Hospital to meet young patients on their annual Christmas visit.
Liverpool Cathedral is celebrating 100 years since its consecration in 1924.
As well as being Britain’s biggest, it is the fifth-largest Anglican cathedral in the world and the seat of the Bishop of Liverpool and the mother church of the Diocese of Liverpool.