LAMC Productions, organiser of the Guns N' Roses concert last Saturday at Changi Exhibition Centre, takes full responsibility for the transport, food and beverage, and other logistical problems experienced by many of the 50,000 concertgoers.
It said it had not hired enough staff for the event, among other reasons.
But it will not be making any refunds for concert tickets, as some disgruntled fans have demanded.
Speaking to The Straits Times yesterday, LAMC co-founder Ross Knudson, 53, said that "maybe it was too big for us".
"We needed a lot more staff, buses and F&B and to manage the site better... We needed a lot more help from the police, the Land Transport Authority (LTA) and SMRT," he said.
"I want to apologise for that. It's a very big endeavour and a very challenging venue to do a show there, but I don't want to make excuses.
"We're not going to be refunding tickets, but we apologise."
In the wake of the concert, which was the American hard rock icons' first in Singapore, social media was ablaze with complaints about the long wait for food, drinks and transportation, as well as issues with RFID (Radio Frequency Identification) wrist tags that were meant to be used for cashless purchases of food and drink.
Some concertgoers said they had to wait for up to an hour to buy food and more than an hour for shuttle buses to leave the venue.
Their biggest grouse seemed to be with the RFID tags, which were given to ticket-holders at the door.
Many concertgoers had bought credits in advance, but could not use them as the food and drinks ran out. There were 10 bars across the two pens, VIP area and inside the hangar.
Mr Knudson said: "We didn't plan out the F&B properly, we should've hired a F&B manager to plan the flow of the audience in each of those pens and allowed people in Pen A to buy F&B from Pen B, where there were more selections."
There was only one food stall in Pen A and three in Pen B.
Mr Knudson said his company was "trying to embrace new technology" with the RFID wristbands, but admitted it should have "launched the wristband with the ticket at the very beginning instead of trying to force it at the last minute".
LAMC will be refunding any balance value in RFID wristbands, but has not disclosed details on how this will be carried out.
Sandpiper Digital Payments Asia (SDP) handled the software and systems for the RFID wristbands. Its managing director James Kane said it had raised concerns with organisers that there were not enough queues and staff at each gate to facilitate the large crowds.
Entrances to Pen A and Pen B had only six queues each; by 7pm, there was a backlog of thousands still waiting to get in.
Sandpiper, which worked with events such as dance music festival Road To Ultra 2015, said that while it had more than enough equipment on site to facilitate the scanning of large numbers of tickets, there were simply not enough staff provided by the concert organiser to do the job.
In a statement sent to the media, the company said: "SDP did not feel that six entry queues for Pen A and Pen B would be adequate for an event of over 30,000 people. However, it is the final decision of the organisers and their team to follow or ignore our recommendations."
Getting in and out of the venue was a major problem too.
Changi Exhibition Centre is accessible only by Aviation Park Road, a narrow two-way road, which saw traffic impeded by ongoing land reclamation works that took place last Saturday.
Mr Knudson said: "We had requested that it be stopped on the day of the show, but (the trucks) kept running all day, causing unnecessary congestion."
While concertgoers made their own arrangements to get to the exhibition centre, LAMC sold tickets at $15 each for a shuttle bus service out of the venue to five destinations - Singapore Expo, Bedok, Tampines, City Hall and Bugis.
Mr Knudson declined to reveal how many buses LAMC had chartered for the night, but the mass exodus of concertgoers resulted in more than hour-long queues to get out and many people getting on the 40-seater shuttle buses without tickets.
Guns N' Roses' show was the second concert to be held at the venue. The first was Metallica's in 2013, which saw 40,000 in attendance and was also organised by LAMC Productions.
It is not deterred from holding future concerts at Changi Exhibition Centre.
Mr Knudson said: "It's a very challenging place, but it has tremendous potential to be the best concert venue in the whole region."
Without elaborating, he added: "I still think it's a better venue than the National Stadium."
But other concert organisers do not share his optimism about the venue.
Mr Matthew Lazarus-Hall, director of St Jerome's Laneway Festival, which held its seventh edition at Gardens by the Bay last month, said of the place: "The location and accessibility to and from it seem to be an impediment to the venue as well as some of the site operations."
Mr Ngiam Kwang Hwa, 55, managing director of concert promoter One Production, agreed, saying Changi Exhibition Centre is "less than ideal".
"There's limited, if any, public transport options and, with 40,000 people trying to get in and out, it's definitely going to be a problem," he said.
Live Nation Lushington, an organiser of large-scale concerts such as the upcoming two-day Coldplay concert at the National Stadium, does not rule out the venue.
But its managing director Michael Roche said: "It has many challenges. All the infrastructure - food, beverage, toilets and transport, which is the biggest issue - would have to be in place."