Browser-cached files got out of sync for staff members at several clients, which caused the Block Editor to fail. Usually, this resulted in a “white screen” (no page content) when trying to create a new post or edit an existing one. Staff could work around this by removing their local cache, which our support staff provided instructions for ad hoc until the issue was resolved more broadly.

First report was 9 Dec at 3:18pm ET as an isolated incident, it was escalated 10 Dec at 11:15 ET for priority action and fully resolved at 3:25pm ET.