Current network status and maintenance

Updates

• Nov 17, 2025 9:16 AM SAST

  The issue is still ongoing; however, we have identified that performing a UEFI OS reinstall should resolve the error.

  Resolved
• Oct 15, 2025 10:15 AM SAST (1 month, 1 day, 22 hours, and 57 seconds earlier)

  After testing, we have found that the new October Windows Server 2025 update KB5066835 is still causing the same boot failures and unexpected disk I/O errors.

  Monitoring
• Sep 23, 2025 11:14 AM SAST (3 weeks, 23 hours, and 1 minute earlier)

  We will continue to monitor closely and address any individual cases as they arise.

  Monitoring
• Sep 16, 2025 12:14 PM SAST (6 days, 22 hours, and 59 minutes earlier)

  We have found that in certain scenarios, running this update causes boot failures and an unexpected I/O error.

  You are encouraged to make regular off-server backups, especially before applying any major Windows updates, providing a fail-safe to restore from.

  If you run the update and encounter the error without having made a backup, you are welcome to contact us, and we will investigate on a case-by-case basis.

  Monitoring
• Sep 15, 2025 12:45 PM SAST (23 hours and 28 minutes earlier)

  We have identified that applying Windows Server 2025 update KB5065426 on certain TruServ servers causes a boot failure with the error: "An unexpected I/O error has occurred."

  We recommend not applying this update until the issue is resolved. Attempts to repair the system - such as reverting updates, rebuilding the boot configuration, and performing BIOS resets - did not resolve the issue.

  Our System Administrators are currently investigating the possible cause and potential fixes.

  Potential Workarounds:

  1. Avoid the KB5065426 Update
     Do not install the 2025-09 Cumulative Update for Microsoft Server Operating System version 24H2 for x64-based Systems (26100.6584) – KB5065426.

  2. OS Reinstall Without Latest Updates
     If you have already applied the update, reinstalling Windows Server 2025 and preventing the KB5065426 update from being installed allows the server to run normally.
     This requires disabling automatic updates.

  Monitoring