Windows 5063878 KB11 causes SSD failures during long backups

If you have installed the latest cumulative update of Windows 11, identified as KB5063878, it is advisable to exercise extreme caution: multiple reports indicate that under certain conditions SSDs can fail during heavy data transfers. Affected units may become undetectable., which increases the risk of corruption or loss of information.

User testimonials and tests shared on technical forums point to the fact that, with long-term copies greater than 50 GB, some drives stop responding and disappear from the system, creating a problem that in some cases requires additional diagnostics to regain access to the affected drive.

What's happening with KB5063878

The security update, associated with the build 26100.4946 de Windows 11 24H2, came to reinforce the system, but in specific scenarios it is causing SSD incidentsSeveral users report that, while in the middle of a file transfer, the drive disappears from Explorer and stops responding to SMART queries, as if it has a physical failure.

Although it does not seem like a massive problem, the trickle of cases es reproducible Under sustained loads and on a variety of machines, both in home and professional environments, especially during long, continuous writes. This behavior has been verified in several configurations.

When and how the failure is reproduced

The most common pattern indicates that the error appears during continuous writes of more than 50 GB. At that point, the drive may become inaccessible and the SMART system stops reporting, suggesting a low-level blockingThe probability of incident increases when the SSD is busy in more than 60% of its capacity.

It has been observed that in units DRAM-less (with HMB) The problem is more sensitive, probably because they rely on system memory for caching. After a reboot, some users report that the drive works again, although in other cases, the failure repeats minutes later, complicating recovery and raising concerns about possible data corruption.

Affected units and controllers

Preliminary reports identify a higher incidence in controllers Phison, although not exclusively. Among the models mentioned by users and specialized media, the following stand out:

• Corsair Force MP600 (Phison E16 Controller)
• Models with Phison PS5012-E12
• SanDisk Extreme Pro M.2 NVMe (Triton MP28 controller)
• Fikwot FN955 (MAP1602 + WDS X3 9070 controllers)
• Kioxia Exceria Plus G4 1TB (Phison E31T Controller)

There are also cases where the drive becomes visible again after a reboot, such as some WD Blue SN5000 2TB (Polaris 3 controller), WD Red SA500 2TB SATA (Marvell 88SS1074), Corsair MP510 960GB (Phison PS5012-E12) or Crucial P3 Plus (Phison E21T) models.

On the other hand, there are models that seem not to be affected, such as Samsung 980/990 Pro or Solidigm P44 Pro, which points to a problem controller, firmware and configuration dependent.

Likewise, incidents have been reported in some Enterprise-class HDD with write-intensive loads, although the main focus remains on the NVMe drives affected by the problematic update.

What Microsoft says so far

For now, Microsoft has not officially confirmed that KB5063878 is the cause of the SSD failure. However, the company has acknowledged another problem: a installation error 0x80240069 in deployments via WSUS/SCCM, which was resolved on August 14, 2025.

The problem related to the units of storage not yet appearing in the public documentation support, so it's considered a matter under investigation. Meanwhile, users continue to report cases, and the situation is being actively monitored.

Recommendations if you have already updated

To minimize risks, it is recommended Avoid continuous copies or writes greater than 50 GB and postpone intensive tasks, such as migrations or lengthy renderings. Additionally:

• Splitting large transfers into smaller blocks to reduce the sudden load on the unit.
• Free up space on your SSD, trying to keep it less than 60% of its capacity to reduce the likelihood of incidents.
• Make backup copies before disk-intensive tasks.
• Consider uninstalling KB5063878 in case of experiencing serious problems, although this should be done with caution due to the impact on system security.

In managed environments, administrators can choose to pause deployment of the update and monitor storage telemetry and SMART alerts on critical devices. Evidence suggests that, although the issue is limited and reproducible in specific scenarios, maintaining caution and prioritizing backups is the safest strategy until Microsoft confirms the full extent of the issue.