Rolling back a recent change did not fix the issue as the company initially anticipated it would.
Always have to come to Twitter to find out if something is up, because Azure and O365 health status says "All is normal". pic.twitter.com/dKnAYnHe8c— Scott Strausbaugh (@strausysatwit) September 28, 2020
In its latest update, the company said: "Our mitigation strategy was successful in allowing users to sign into the previously impacted services.
"Our internal monitoring has validated this recovery and we have received positive confirmation from customer reports.
The report said: "Users would be unable to access Outlook.com, Microsoft Teams including Teams Live Events, and Office.com.
"Additionally, Power Platform and Dynamics365 properties are affected by this incident."
iTWire has confirmed that the outage is not limited to any one region, with users in Australia also being locked out.
"Existing customer sessions are not impacted and any user who is logged in to an existing session would be able to continue their sessions," the Microsoft notice said.
"We've identified that reverting the recent change did not alleviate impact to Microsoft services as expected. We're working to explore additional options for mitigation.
It’s getting “better”... Microsoft engineers have huge responsibility now - when productivity of millions depends on them. pic.twitter.com/pkQdqeLjDI— Oleg Melnikov (@omelnikov) September 28, 2020
"Any user may experience access problems for Microsoft 365 services."
Contacted for comment, former NSA hacker Jake Williams said: "It's a good day to plan for how centralising things like Azure Active Directory will impact you in an outage scenario.
"Many who move to AAD do so for security reasons, usually in hopes of protecting confidentiality of their data. But, of course, security includes availability too."