An outage has been declared since 2021-10-26 4:52 AM CEST in NEU Region.
Issue is still ongoing and progress can be tracked here
Iridias - Azure CXP Engineering (microsoft.com)
Below the latest update.
Title: Environment inaccessible
User Impact: Users may be unable to access your environment.
Current Status: After our investigation, we identified that a recent deployment had introduced a code misconfiguration to a portion of the database infrastructure responsible for environment access. We are performing a rollback of the deployment.
Incident Start Time: Tuesday, October 26, 2021, at 2:52 AM UTC
Next Update: Tuesday, October 26, 2021, at 7:30 AM UTC, to allow additional time for the rollback to complete.
UPDATE 1:45 PM CEST
CSS just received from operations that ALL PROD environment in North Europe (NEU) are back online. Still some sandbox environment is getting back online. It might take just few minutes more for these ones.
Below you will find the resolution of the Dynamics 365 Outage item.
Title: Environment inaccessible
User Impact: Users may be unable to access your environment.
Final Status: The rollback has completed. We have verified via telemetry that environment access has been restored.
Incident Start Time: Tuesday, October 26, 2021, at 2:52 AM UTC
Incident End Time: Tuesday, October 26, 2021, at 11:45 UTC
Preliminary Root Cause: A recent deployment had introduced a code misconfiguration to a portion of the database infrastructure responsible for environment access
Next Steps: We're reviewing our standard service update procedures to avoid similar impact in the future.