Word is circulating around the Internet that the latest Windows 11 update may be causing some potentially serious problems for SSD owners. More specifically, some users in Japan have reported that their SSDs were corrupted, making it impossible to read files or even mount the drive properly. Users also reported losing out on SMART features, which allow SSDs to self-monitor and report issues. 

The update in question is KB5063878, which Microsoft launched to the public on Aug. 12. It’s a Windows Secure Boot update that resets certification for devices that are set to expire in June 2026. There doesn’t appear to be anything about the update that might cause concern, but some scattered user reports indicate differently.

Mashable has not been able to independently verify these reports, so at this point, we would classify this news as a rumor.

Per Wccftech (and as spotted by Tech Radar), users began reporting the issue on social media in the days following the update.

Here’s what they reported: The user writes a large amount of data to the drive. Once done, the drive vanishes from the OS, becoming completely inaccessible to the user. After a reboot, Windows is unable to read the partition, and the drive’s SMART features become inaccessible. According to Japanese PC enthusiast Necoru_cat, there is also a high likelihood of system file corruption. 

In order to cause the issue consistently, Necoru_cat says that a write needs to be approximately 50GB on an SSD that is at least 60 percent full, with some SSDs causing more problems than others. Japanese blog NichePCGamer has compiled a list of potentially problematic SSDs based on user tests, along with links to where they were reported. Users have reported problems with SSD drives from Corsair, Phison, Fikwot, Maxio, and others.

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According to Wccftech, it’s possible the Windows 11 update caused a bug that “mishandles long sequential writes,” causing the drive to be lost to the OS. 

Should I be concerned?

Yes and no. There are a handful of reports of the update causing SSD problems on X, but the overwhelming majority of these users seem to be in Japan, which may indicate a region-specific issue. We were able to find some additional reports from folks on Reddit, but could not verify their location. 

If the issue were easy to trigger, we’re sure more reports would exist, as the update has already been out for six days. Thus, it doesn’t appear to be a widespread problem, and it’s likely not something you’ll run into with day-to-day use. With that said, we recommend being careful with any large data writes, just in case. 

And if you want to avoid any potential risk, here are some tips to keep your drives safe: 

1. Back up your data as soon as possible. The bug appears to hit at random, so it’s better to be safe than sorry. 

2. If you don’t have KB5063878 installed, pause Windows updates. You can do this by opening Windows Settings, navigating to Windows Update, and the option should be there. Unpause once the next set of Windows updates comes out. 

3. If you do have KB5063878 installed, leave Windows updates enabled. You’ll want to get the fix as soon as possible. 

Should you run into the issue, collect as much data as you can and report it directly to Microsoft via the Feedback Hub.