An S Club concert had to have a “partial evacuation” before the show was restarted.
M&S Bank Arena Liverpool said that it will conduct a “full investigation” into the “minor incident” but did not disclose details of the issue.
The Monday performance had been rescheduled from October 13 due to issues with the venue’s power supply.
In a post on X, formerly Twitter, M&S Bank Arena Liverpool said: “Tonight, as S Club were close to finishing their set at the arena, there was a minor incident which triggered a partial evacuation.
“The issue was resolved quickly and we were able to restart the show. We will be launching a full investigation.
“The safety of the audience, staff and performers is always our primary concern.”
The pop band, formerly known as S Club 7, kicked off their 25th anniversary reunion tour with a show in Manchester on October 12.
Less than 24 hours later they had to cancel their Liverpool date, saying on Instagram that they were “beyond devastated”.
They told fans the venue had “an unforeseen technical issue impacting their power supply and therefore your safety”.
The statement also said: “We can’t begin to express how sorry we are.
“Especially as we know so many of you have travelled great distances to join us tonight.
“But your safety is our priority always. We’re rescheduling tonight’s performance in Liverpool to Monday October 30 and all tickets remain valid.
M&S Bank Arena also apologised on X and said it understood the group and fans would be “very disappointed but as the safety and comfort of our visitors is our utmost priority the show cannot proceed as planned”.
“As the technical issue is in an isolated area of the campus, we are not anticipating that any other events will be affected,” the statement said.
S Club, which now comprises Rachel Stevens, Jon Lee, Tina Barrett, Jo O’Meara and Bradley McIntosh, head to the US for performances in Chicago, Los Angeles and Boston next month.
Band member Hannah Spearritt has not taken part this year and Paul Cattermole died in April, shortly after the tour was announced.