Thousands of people were offered refunds and a free Legendary Pokémon to make up for the disappointment.
Last week’s Pokémon Go Fest event in Chicago was meant as a global celebration of the smash hit game’s first anniversary.
Instead it was beset by ticket inflation, huge wait lines for admission, and overloaded cellular service and technical problems with the game itself.
Players were furious and the company behind the game, Niantic Labs, had to issue refunds and in-game items to appease the fans .
John Hanke, Niantic’s boss, has now apologised for the failure in a lengthly blog post and explained some of what went wrong on the day.
“It was obviously an incredibly stressful and disappointing day for all of us,” he wrote.
“Both I personally and all of Niantic apologize for the inconvenience and frustration.”
According to Hanke, the company had to reconfigure the games servers during the event due to the “technical issues” it experienced – perhaps due to organising the co-operative raids and the unveiling of the new Legendary Pokémon.
However, it also appears that massive latency issues meant many players couldn’t even get into the game, let alone capture any of the creatures. And for that, Hanke lays the blame at the door of the cellular networks.
“A more protracted problem was caused by oversaturation of the mobile data networks of some network providers. This caused many attendees to be unable to access Pokémon GO or other Internet services.
“On the pure network access issue, we provided detailed estimates on attendance and required data throughput per user to our event partner who worked with the major carriers to allow them to plan for adequate coverage.
“Some carriers deployed Cellular on Wheels (COWs) to extend their capacity. In other cases the providers deemed them unnecessary based on other infrastructure already in place at the site. Users reported different levels of success with these providers.”
Hanke goes on to state that as the day progressed the services got better and players were able to enjoy the game. Over the course of the weekend, players in Chicago caught more than 7.7 million Pokémon and 440,000 Legendary Pokémon.