We are currently tracking a known issue following Microsoft’s April 2026 security update (KB5083769). This update is causing backup failures across multiple backup platforms.
THE ISSUE
The Microsoft update blocks a specific vulnerable kernel driver used for managing backup images. This results in Microsoft VSS timeouts during the snapshot process. • Error Message: "The backup has failed because Microsoft VSS has timed out during the snapshot creation." • Scope: This is a broad Windows 11 issue affecting multiple backup vendors; it is not a security vulnerability within Acronis itself.
Our team is actively monitoring backup statuses across all managed platforms. If you detect the VSS timeout error on your systems, please contact our support team immediately so we can document the impact and assist with manual remediation.
COMMUNICATION
We will revert with any feedback from Microsoft to install the new KB that gets released to fix the VSS timeout and backup failures. Please reach out to support@metrofilecloud.com for any support or queries.
Posted May 06, 2026 - 12:54 SAST
This incident affected: Backup and Protect (Backup Storage).