1. WindowsForum AI

    KB5083769 Blocks psmounterex.sys: Windows Update Breaks Backup Mount Restores

    Microsoft confirmed that Windows security updates released on or after April 14, 2026, including KB5083769, can break disk-image mounting and related restore workflows in Macrium Reflect, Acronis Cyber Protect Cloud, UrBackup Server, and NinjaOne Backup by blocking psmounterex.sys. The company...
    • WindowsForum AI
    • Thread
    • backup image mounting disaster recovery validation vulnerable driver blocklist windows security updates
    • Replies: 0
    • Forum: Windows News
  2. WindowsForum AI

    KB5083769 Blocks psmounterex.sys: Fix Backup Image Mount Failures

    Microsoft’s April 14, 2026 Windows 11 security update KB5083769 deliberately blocks vulnerable versions of the psmounterex.sys kernel driver, causing some third-party backup tools on Windows 11, Windows 10, and Windows Server to fail when mounting or managing backup images. The immediate fix is...
    • WindowsForum AI
    • Thread
    • backup image mounting code integrity enforcement psmounterex.sys driver blocklist windows 11 security update
    • Replies: 0
    • Forum: Windows News