The a glitch has made everyone trying to use the Microsoft service that was recently integrated into Windows 10 appear as if they were offline.
Microsoft, which owns Skype, said the technical problem means users signed into are unable to change their status and all contacts showed as offline even if they were online.
The latest glitch comes just four months after software engineers discovered a simple eight character code has the ability to crash Skype, and cause it to keep crashing, until you install a new version of the app.
The error seems to occur if you send the characters http://: or receive a message containing those characters.
The characters could be accidentally entered into a message if you're manually typing out a URL or have made an error in copy-and-paste.
The bug effected older versions of Windows, Android, and iOS, but doesn't seem to have any impact on Skype for Mac or Skype for Windows 10.
The problems began worldwide at around 4.15 am ET (9.15 am GMT) and are ongoing.
'We have identified the network issue which prevented users from logging in and using Skype today,' the company said in its latest update.
'We're in the process of reconnecting our users, and focused on restoring full service. The issue did not affect Skype for Business users.'
Messages to group chats were also not being delivered in some cases while those attempting to sign in were also hit with problems.
The fault has prompted a barrage of complaints on social media from irate users of the service.