It’s not just you, Microsoft has confirmed that Azure Active Directory service is down for many users around the world. This issue affects Azure users in Americas, Europe and Asia Pacific, however Azure Government users are not affected from this outage.
Users in these regions may experience difficulties when attempting to authenticate into resources which are dependent on Azure Active Directory. Microsoft is aware of this issue and is actively investigating to resolve this issue.
Azure Active Directory (Azure AD) is Microsoft’s multi-tenant, cloud based directory and identity management service. Even though all other Azure services are up and running, users may not be able to start using them if it requires Azure AD based authentication. Some Office 365 services which depend on Azure AD is also facing access issues, Microsoft is aware of this issue and working on resolving it ASAP.
Update: Azure AD service is now up and running without any issues for everyone.