backup solutions Archives

Winsage

May 8, 2026

Windows update is breaking backups, and here’s how you can fix it

A recent Windows update, KB5083769, released on April 14, 2026, blocks the psmounterex.sys driver, disrupting the functionality of third-party backup software like Acronis Cyber Protect Cloud, Macrium Reflect, and NinjaOne. This driver is essential for loading and mounting backup storage images. Users may encounter errors related to Microsoft VSS during backup attempts. The update is a security enhancement, not a bug, and users are advised to upgrade their backup software to versions that use a newer driver or temporarily uninstall the KB5083769 update. It is recommended to check for updates from the backup software provider and pause Windows Updates to prevent automatic reinstallation of the problematic update until a fix is available.

Winsage

May 7, 2026

My Windows 11 backup broke after KB5083769 — Microsoft says this simple fix might save your files

The Windows 11 security update KB5083769, released on April 14, 2026, introduces changes to the psmounterex.sys driver, causing compatibility issues with third-party backup solutions such as Macrium Reflect, Acronis Cyber Protect Cloud, UrBackup Server, and NinjaOne Backup. Microsoft states this is a necessary security adjustment, not a bug. The update also adds known vulnerable kernel drivers to a blocklist to enhance system security. Users can check if a driver is blocked by using the Event Viewer and looking for Event ID 3077 associated with a specific Policy ID.