Skype has credited the recent outage that prevented millions of users from accessing the service to a bug in an older Skype client for Windows operating system.
Several support servers that are responsible for offline instant messaging overloaded, Skype's chief information officer (CIO) Lars Rabbe, said in a blog post.
Due to this, some Skype users failed to get responses as quickly as they earlier used. Meanwhile, a software bug in Skype's Windows client version 220.127.116.11, prevented the client from responding to the delayed responses causing it to crash.
As the affected software was used by around half of Skype users, the resultant crash caused several supernodes, which are phone directories in Skype lingo, to crash as well, preventing millions of users from using the service.
“Lessons will be learned and we will use this as an opportunity to identify and introduce areas of improvement to our software, further assess and invest in capacity and stability, and develop better processes for outage recovery and communications to our user base,” Rabbe said.