Today Microsoft (Skype team) announced that starting 7th of July 2015 there will be only version of Skype for Windows left. As you probably aware currently there are two versions - Skype for desktops and Skype for modern Windows (aka metro app). Two versions provides slightly different experience which maay be confusing for users. It was decided to get rid off one.
From 7 July, 2015 you’ll no longer be able to sign into the Skype for modern Windows app.
If you dont' have Skype for desktop it's time to move to it