Users of Acer computers running Windows 11 25H2 have reported boot failures following the installation of Microsoft Secure Boot certificate updates. The issue manifests as a Secure Boot Violation error, followed by a message indicating that the UEFI firmware cannot identify a bootable device.
The problem arises when users install the new Microsoft security update before updating their device firmware. Microsoft began distributing the 2023 certificate chain to replace the 2011 versions, which are set to expire in 2026. The update is delivered automatically via Windows Update in a phased rollout.
According to user reports, the issue was first observed on August 31. Disabling Secure Boot in the UEFI settings allows the system to boot again, although this action disables the boot chain signature verification. Acer has released firmware updates that ensure compatibility with the new certificates.
