The British-born Easy on Me singer postponed her exclusive new residency at The Colosseum at Caesars Palace Hotel just 24 hours before its opening night.
“I’m so sorry, but my show ain’t ready,” she said in the video posted to Instagram on Thursday.
The entertainer said that all of the shows would be rescheduled, and blamed it on “delivery delays and Covid”.
“We’ve tried absolutely everything we can to put it together in time and for it to be good enough for you, but we’ve been absolutely destroyed by delivery delays and Covid,” she said.
“Half my crew and team are down with Covid and still are, and it’s been impossible to finish the show.
“I’m gutted – I’m sorry it’s so last minute, we’ve been awake for over 30 hours trying to figure it out and we’ve run out of time.
“I’m so upset and I’m really embarrassed and so sorry to everyone that traveled [to the show]. I’m really, really sorry.”
And she added: “We’re going to reschedule all of the dates, we’re on it right now.
“I’m gonna finish my show and get it to where it’s supposed to be. We’ve been up against so much and it just ain’t ready. I’m really sorry.”
The Las Vegas Weekends with Adele residency was announced in November, and she was due to perform two shows each weekend until 16 April 2022.
Her fans snapped up the 100,000 tickets within six hours when they went on sale in December, setting a record per-show average gross of $2.2m (£1.6m).
Ticket prices ranged from $85 to $600 for the balcony and between $860 and $5,000 for the lower section of the 4,200 seat venue.