On 11.11.2024 1:57 PM we noticed that the AEM Sidekick was no longer able to talk to the admin service. As a result, customers were no able to execute any publishing operations through the sidekick.

The reason was the removal of a CORS header which was believed to no longer be necessary. This caused the browser to block requests outgoing from the sidekick to the admin. After reverting the commit at 2:00 PM that caused the issue, the sidekick was again operable.

During that outage, the Admin HTTP API stayed functional.