Microsoft 365, Office users hit by wave of ‘30088-27’ update errors

Microsoft 365 and Office users are encountering persistent “30088-27” errors when checking for updates—affecting C2R installations (Office 2016/2019/2021) and the latest Version 2406 (Build 17726.20126). A Microsoft community moderator recommends rolling back to a previous build and disabling automatic updates as a temporary workaround, while Microsoft has not yet provided an official fix. The report also references other recent Outlook issues and rollbacks, indicating ongoing stability challenges rather than a security incident.