Storage is currently experiencing a worldwide outage impacting HTTPS operations (SSL traffic) due to an expired certificate," according to a message on the Windows Azure Service Dashboard that remained posted Friday night. "HTTP traffic is not impacted. We are validating the recovery options before implementing them. Further updates will be published to keep you apprised of the situation. We apologize for any inconvenience this causes our customers."

Some forum commenters initially mulled over possible causes and mitigation tactics, such as changing an app's configuration to HTTP from HTTPS.