Microsoft recently released a new Windows 11 update, the KB5063878, with the build 26100.4946. Per the patch note, this latest version is supposed to address the security issues of the operating system, but it seems that the update is causing SSD failures during heavy file transfers.
As reported by X user @Necoru_cat, the issue happens when attempting continuous file transfers larger than 50 GB. The OS apparently can not recognize the SSD after a long instance of the transfer, and if the updated PC is restarted, the drive becomes inaccessible. The X user did some internal testing and noted that SSDs with Phison NAND controllers are more prone to this problem, but it seems not all drives are affected.
Japanese outlet NichePCGamer has also reported on the issue, and the outlet has listed the known SSDs that are facing this apparent Windows 11 KB5063878 issue, which are:
- Corsair Force MP600 (Phison E16 controller)
- Phison PS5012-E12 (Phison PS5012-E12 controller)
- SanDisk Extreme Pro M.2 NVMe (Triton MP28 controller)
- Fikwot FN955 (MAP1602 + WDS X3 9070 controllers)
- Kioxia Exceria Plus G4 1 TB (Phison E31T controller)
Per the list, it seems that it’s not just drives with Phison controllers that are susceptible to this problem, as it includes drives like the SanDisk Extreme Pro. X user @Necoru_cat later reported that some of the SSDs may become inaccessible after the issue occurs, but recover after rebooting. These drives include:
- WD Blue SN5000 2 TB (Polaris 3 controller)
- WD Red SA500 2 TB SATA (Marvell 88SS1074)
- Corsair MP510 960 GB (Phison PS5012-E12 controller)
- Crucial P3 Plus (Phison E21T controller)
As of now, the issue seems relatively less widespread than other major Windows-related problems, as not many user reports are popping up in public forums. It’s also worth noting that Microsoft and SSD manufacturers have yet to verify this Windows 11 update issue, but users with an updated PC and an SSD with a Phison controller should avoid making continuous transfers larger than 50 GB. It would also be a good idea to avoid updating to KB5063878 now or rolling back to the previous version if already updated.


Abid’s journey as a technophile began when he first assembled his PC. Since then, his insatiable curiosity has driven him to delve into every aspect of this rapidly evolving technological landscape. And as a tech reporter, he prioritizes transparency, accuracy, and unbiasedness.