An outage hit Microsoft's main cloud software products, including Outlook.com, Hotmail, Office 365 and OneDrive, last night with all geographies appearing to have been affected.
Between roughly 4pm and 7pm BST, users trying to access services that use the login.live.com authentication portal were unable to do so.
This would have been most apparent to those using the browser, where the login page would fail to load and clicking the 'login' link sometimes resulted in a file download. However, the Skype desktop client was also affected and users were unable to send or receive emails from their Outlook, Hotmail or Live accounts using clients on their phones or desktops either.
One notable exception, however, is that those using Outlook with Windows 10 were still able to receive emails throughout the disruption period.
All of the services listed and more use login.live.com as a central authentication portal. They also all run on Microsoft's Azure cloud infrastructure, although according to the service dashboard, there was no problem with Azure during the outage.
Down Detector recorded 7,995 outage incidents just before 7pm last night but shows far fewer now, and it seems most users can now login, as confirmed by downforeveryoneorjustme.com and independently by IT Pro. But Microsoft has indicated that some issues remain.
In a statement to IT Pro, a Redmond spokesperson said: "We are aware that some users are experiencing difficulties signing in to some services. Engineers are working to fully resolve this as soon as possible."
The root cause of the outage, the total number of customers affected and whether there was any risk to customers at any point is as yet unclear.
