Skype has come clean on the cause of the major outage that knocked its service offline for 15 hours on Monday.
In a blog post by Gurdeep Pall, corporate vice president for Information Platform and Experience at Skype, said that a "larger-than-usual configuration change" for causing the issue.
"We released a larger-than-usual configuration change, which some versions of Skype were unable to process correctly therefore disconnecting users from the network," he wrote.
"When these users tried to reconnect, heavy traffic was created and some of you were unable to use Skype’s free services, including messaging, presence, and contact list management.
"Others could not sign in or out of Skype altogether, or make calls to landlines or mobile phones."
Pall apologised for the incident, noting that users of the service expect better.
"No matter how quickly we were able to resolve this issue, it would not have been quick enough. We know many of you needed to use Skype during the outage, and finding that you couldn’t would have been incredibly frustrating."
The incident began on the morning of Monday, 21 September, with users finding themselves unable to send instant messages on the service, or see users' presence settings.
Skype confirmed it was aware of the problem in a blog post, citing a network issue, during the afternoon, before confirming at just before midnight that the service was back to normal.
"We have identified the network issue which prevented users from logging in and using Skype today. We're in the process of reconnecting our users, and focused on restoring full service," wrote web quality assurance engineer Leonas Sendrauskas.
It was also confirmed that Skype for Business users were not affected by the outage.
Skype first acknowledged the issue during Monday morning but did not give any indication of the cause.
“Some of you may experience problems with Skype presence and may not see online. We have detected an issue with the status settings of Skype,” wrote Sendrauskas.
“Affected users will not be able to change their status, their contacts will all show as offline and they will be unable to start Skype calls to them.
Skype also confirmed the outage on Twitter, but gave no more explanation as to the cause.
Skype, which is now owned by Microsoft, claims that the service is still delivering instant messages. However, the V3 team and others have not been able to send messages, suggesting this may be a new issue since the blog post was written.
Microsoft merely stated it was working on the issue when asked by V3 for more information on this issue.
“We are working hard to fix an issue which is preventing some users from logging in and using Skype.”
Skype said its service was still available via the Skype for Web client. However this suggestion appears to have backfired as the service is now mostly unavailable, with the service either failing to load or an error message appearing apologising for the lack of service.
Skype users have taken to Twitter to express their frustration at the situation.
Suffering without Skype #skypeoutage— Mary (@NeonChipmunk) September 21, 2015
Comcast's £29.7bn winning bid more than twice the £13.7bn Rupert Murdoch valued Sky at just eight years ago
A nuclear strike has been considered, but Bruce Willis is nowhere in sight
Spray-on antenna could enable seamless integration of antennas with everyday objects
Parker Solar Probe, TESS and GOLD missions will deliver exciting data, claims NASA