Beware the August 2025 Windows 11 Update — It Could Vanish Your SSD
What’s Going On?
A wave of recent reports has raised alarms that one of Microsoft's August 2025 updates for Windows 11—namely KB5063878 (and in some cases KB5062660)—may be causing storage devices, especially SSDs, to disappear under heavy write workloads. Users say the drives vanish from File Explorer, become unreadable in BIOS, or even suffer from data corruption. Some systems reportedly experience permanent loss.
Who’s Affected?
Though the issue appears rare, several SSD models and controllers are being flagged:
Phison-controlled SSDs, especially DRAM-less variants.
Specific models reported include Adata SP580, Corsair Force MP600, Kioxia Exceria Plus G4, Fikwot FN955, SanDisk Extreme Pro M.2 3D, and others.
A test of 21 drives found 12 became inaccessible during heavy writes; the WD SA510 2TB drive was unrecoverable even after a reboot.
Reports suggest HDDs may also exhibit similar symptoms under strain.
How Does It Happen?
Most incidents occur when:
The drive is over 60% full.
Subjected to continuous writes of 50 GB or more.
A reboot may temporarily restore access, but the issue often reoccurs under similar load conditions. In some cases, files become completely corrupted.
Stakeholder Reactions
Microsoft acknowledges the reports and says it’s investigating.
Phison has confirmed awareness of the issue with updates KB5063878 and KB5062660 and is working with partners on a solution.
A simultaneous bug (from KB5063875) disrupted recovery tools like “Reset this PC,” but Microsoft released an out-of-band fix (KB5066189) for that—though that patch does not appear to address the SSD issue.
What Reddit Users Are Saying
On r/hardware, one user summarized:
“The issue purportedly surfaces during heavy write operations… especially when continuous sustained writes approach 50 GB on drives and exceed 60 per cent controller usage.”
And in a gaming forum, a user cautioned:
“Prolonged writing of 50 GB or more can cause your SSD to become corrupted and unreadable by your OS. It’s confirmed across multiple SSD brands.”
Action Steps for Users & Readers
Pause heavy writes if you're on Windows 11 with updates KB5063878 or KB5062660 installed.
Backup critical data now using reliable external drives or cloud storage.
Hold off on large installations or game updates until a fix is confirmed.
Watch for updates from Microsoft and your SSD manufacturer—especially Phison-related advisories.
If you’ve already installed the problematic updates and suspect corruption, avoid rebooting unnecessarily and check if recovery tools—like “Reset this PC”—are still functional. Apply the KB5066189 patch if not already done.
TL;DR Summary
The August 2025 Windows 11 update (KB5063878) is linked to SSD disappearance and corruption during heavy writes—especially on drives over 60% full and writing 50 GB+. Microsoft and Phison are investigating, but no definitive fix is out yet. Exercise caution, backup, and stay informed.