Parents who were tearing their hair out since last Thursday breathed a sigh of relief when Roblox finally returned online yesterday. While people speculated the problem was due to a cyberattack or even the result of a Halloween giveaway, the company has blamed the outage on an “internal system issue.”

At 4 pm PST on October 28, Roblox’s 200 million users, two-thirds of whom in the US are aged between 9 and 12, couldn’t access the platform due to a server disruption. On Sunday, the company tweeted that it was working to resolve the situation and had identified “the root cause as [an] internal system issue.”

Many believed that the fault was due to an in-game Chipotle promotion attracting too many people. A giveaway called the Chipotle Boorito Maze let players earn daily items by navigating a maze while collecting real ingredients and avoiding monsters, and reaching the center granted a free avatar item. Additionally, players could get a free burrito—with $1 million worth up for grabs—by dressing in “a Chipotle-inspired costume.”

Despite the Chipotle promo beginning just before the problems began, Roblox confirmed that “this outage was not related to any specific experiences or partnerships on the platform.” At 12.50 PST on Sunday, October 31, some players were allowed to reconnect, with the outage officially coming to an end at 4.45 pm.

Roblox also confirmed that the platform wasn’t taken down by “external intrusion,” ruling out hackers, ransomware, and the like. David Baszucki, Roblox founder and CEO, explained that “a core system in our infrastructure became overwhelmed, prompted by a subtle bug in our backend service communications while under heavy load.

This was not due to any peak in external traffic or any particular experience. Rather the failure was caused by the growth in the number of servers in our data centers. The result was that most services at Roblox were unable to effectively communicate and deploy.”