Microsoft Reportedly Investigating Windows 11 KB5063878 SSD Failure Reports

Microsoft has finally acknowledged reports of SSD failures linked to the August update for Windows 11 24H2. The issue, first flagged by @Necoru_cat on X and later picked up by Japanese outlets, appears to surface after installing KB5063878 (Build 26100.4946).

Today, folks over at Windows Latest reported that Microsoft confirmed that it’s working with partners like Phison to investigate the problem. The company hasn’t advised users to uninstall KB5063878 yet, hinting that the problem remains rare and highly workload-specific.

What’s the backstory?

Well, Windows 11 users have been reporting that their SSD suddenly vanishes from Windows, sometimes even the BIOS, with the partition showing as RAW. In other cases, File Explorer crashes, SMART becomes unreadable, or I/O errors appear mid-task.

According to reports, the bug emerges under heavy write loads, like updating massive games such as Cyberpunk 2077 or Honkai: Star Rail. Interestingly, the failures seem isolated. Most cases come from Japan, suggesting a workload pattern specific to local usage.

Early findings suggest that SSDs using Phison controllers are more vulnerable, though isolated reports also mention InnoGrit and Maxio chips. Drives from Samsung and Seagate don’t appear to be affected.

The exact trigger seems to involve SSDs with more than 60% capacity filled and a write workload of 50GB or more in one go. While some users recovered drives with a reboot, others weren’t so lucky, facing corrupted partitions that required deeper recovery tools.

For now, unless you’re running massive game updates on a nearly full SSD, you probably won’t encounter this issue. We are hoping that Microsoft will soon roll out a patch to mitigate the issue.