SSD Disappeared After Windows KB5063878 Update, Should Be Worried and What Should Do?

Is the Windows 11 KB5063878 Update Really Breaking SSDs, or Is It Just a Myth?

Concerns have recently surfaced about a Windows 11 security update from August 2025, with some users worried it could be causing serious problems for their solid-state drives (SSDs). Talk of “bricked” or failing drives spread quickly online, causing alarm. However, after thorough investigations, the companies at the center of these reports have stated that the update is not to blame.

Here is a clear breakdown of what happened, what the experts found, and what it means for you.

What Problems Were Users Reporting?

The issue first gained attention in mid-August 2025, following the release of a routine security patch, update KB5063878, for Windows 11 version 24H2. A small number of users began reporting a frightening problem: their SSDs would suddenly vanish from the system, making their files and data completely inaccessible.

These failures were not random. They seemed to happen under a very specific set of circumstances:

• The computer was running Windows 11 version 24H2 with the KB5063878 update installed.
• A large amount of data, typically 50GB or more, was being written to the drive in one go.
• The SSD was already quite full, with reports suggesting it was 60% to 80% full or more.

When these conditions were met, the drive would sometimes disappear as if it had been unplugged. While some people found that restarting their computer brought the drive back, others were not so lucky and lost access to their data. The reports mentioned a variety of popular SSD brands, including those with controllers from major manufacturers like Phison and InnoGrit.

How the Story Gained Traction

The news spread rapidly after initial posts on social media platforms like X (formerly Twitter) and discussions on Reddit forums. Tech news websites also picked up the story, amplifying the concerns. With headlines suggesting a Windows update could destroy expensive hardware, many users grew worried. The situation was concerning enough that both Microsoft, the creator of Windows, and Phison, a leading manufacturer of SSD components, launched official investigations.

The Official Investigations: What Microsoft and Phison Found

After weeks of speculation, both companies released the findings of their extensive testing. Their conclusions were clear and surprising to many who had followed the story.

Microsoft’s Conclusion: No Link Found

Microsoft announced that after a thorough investigation, it found no evidence connecting the KB5063878 update to the reported SSD failures. The company analyzed service alerts, user feedback, and internal data but did not see any unusual increase in SSD failure rates that would point to a problem with the update. In a formal statement, Microsoft confirmed it found “no connection between the August 2025 Windows security update and the types of hard drive failures reported on social media”.

Phison’s Deep-Dive: Thousands of Hours of Testing

Attention also focused heavily on Phison, as their controllers are used in many different SSDs. The company took the reports very seriously and conducted an exhaustive investigation to see if its hardware was at fault.

Phison’s testing was incredibly thorough:

• It dedicated over 4,500 cumulative hours to testing the drives in question.
• It performed more than 2,200 test cycles to try and recreate the problem.

Despite this rigorous process, Phison stated it was unable to reproduce the issue. No drives failed in the way users had described. This led Phison to conclude that its products were not the cause of the problem.

Adding to the complexity, Phison had to combat misinformation when a fake document began circulating that falsely claimed a list of its controllers were faulty. Phison denied creating the document and confirmed that its official testing showed no such problems.

So, What Is Really Going On?

If both Microsoft and Phison say their products are not at fault, why did some users experience these failures? While there is no single confirmed answer, the investigations point away from the Windows update being the direct cause. The issue appears to be far less widespread than the initial headlines suggested, affecting only a tiny fraction of users.

The most likely explanation is that these incidents are coincidences. The drives that failed may have already been nearing the end of their lifespan or had underlying issues. The strain of writing a very large file to a nearly full drive could have been the final push that caused an already-vulnerable drive to fail. The timing of the Windows update appears to be just that—a coincidence.

An Advisor’s Guide: What Should You Do?

Navigating tech news can be confusing, especially when it involves your data and hardware. Based on the official findings, here is some simple, level-headed advice.

Don’t Panic

The most important takeaway is that there is no widespread issue causing SSDs to fail because of this Windows update. The investigations by Microsoft and Phison provide strong evidence that the update is safe.

Back Up Your Data

This situation serves as an excellent reminder of the single most important rule in computing: always have a backup of your important files. Whether you use a cloud service or an external hard drive, regular backups protect you from any kind of hardware failure, regardless of the cause.

Avoid Strain on Your Drive

As a general best practice, it is wise to avoid filling your SSD close to its maximum capacity. It is also a good idea to avoid moving exceptionally large files if the drive is already under heavy load. Phison also recommends that users with heavy storage workloads install heatsinks on their SSDs to help with cooling and performance.

Report Genuine Issues

If you believe you are experiencing a problem with your hardware after an update, the best course of action is to report it directly to Microsoft through the official Feedback Hub. This provides engineers with the data they need to investigate potential bugs.

While you have the option to uninstall Windows updates, it is generally not recommended unless you are directly instructed to do so by the manufacturer, as updates often contain critical security fixes that protect you from malware. Based on the current evidence, uninstalling KB5063878 is not necessary for the vast majority of users.