Update 3: Now CEO Tony Bates has provided further explanation and apologies. 

Update 2: Parkes provided another update on the issue today:

An update on the downtime which has been affecting many of you around the world: the ability of one Skype user to find another relies on what we call ‘supernodes’, and yesterday, a number of these failed due to a software issue, which we’ve now identified. Our engineers are working to resolve the problem.

Millions of you are already reporting that you can now sign in to Skype normally, and we estimate that there are already almost 5 million people online. As a guide, this is around 30% of what we’d expect at this time of day – and that number is increasing all the time. Unfortunately, it’s not possible for us to predict on an individual level when you’ll be able to sign in again, and we thank you for your patience in the meantime.

It’s worth noting that our enterprise product, Skype Connect, is working normally, though Skype Manager and our other web-based functions will continue to stay offline for a little longer. Additionally, features like group video calling will take longer to return to normal.

Update: Parkes says on the official Skype blog:

Skype isn’t a network like a conventional phone or IM network – instead, it relies on millions of individual connections between computers and phones to keep things up and running. Some of these computers are what we call ‘supernodes’ – they act a bit like phone directories for Skype. If you want to talk to someone, and your Skype app can’t find them immediately (for example, because they’re connecting from a different location or from a different device) your computer or phone will first try to find a supernode to figure out how to reach them.

Under normal circumstances, there are a large number of supernodes available. Unfortunately, today, many of them were taken offline by a problem affecting some versions of Skype. As Skype relies on being able to maintain contact with supernodes, it may appear offline for some of you.

What are we doing to help? Our engineers are creating new ‘mega-supernodes’ as fast as they can, which should gradually return things to normal. This may take a few hours, and we sincerely apologise for the disruption to your conversations. Some features, like group video calling, may take longer to return to normal.

Original Article: Skype has been having troubles with sign-ins today, and millions of people have lost their connections on the service. Little is known about the cause of all of this, but just do a Twitter search for Skype and you’ll see that a lot of people are less than thrilled. 

Skype is on it, at least. The company posted the following tweets on Twitter:

Peter Parkes with Skype’s communications team told ReadWriteWeb, "If you’re already signed in, you should be able to continue using Skype as normal."

Some people are apparently able to sign in to the service, but have lost their contacts. 

The outage has already caused a big blow to Skype’s reputation. Influential tech blogger Om Malik notes, "The outage comes at a time when Skype is starting to ask larger corporations for their business. If I am a big business, I would be extremely cautious about adopting Skype for business, especially in the light of this current outage."

There have been a lot of high profile outages lately. Some have laste longer than others. It will be interesting to see how Skype handles the damage control with this one.