New Windows 11 24H2 updates released this month have caused problems for some SSD and HDD drives. This has been linked to the KB5063878 security update and the KB5062660 preview update, both of which appear to trigger errors during heavy write operations.
The bug occurs during transfers of more than 50GB when the SSD is more than 60% full. In these cases, some drives become inaccessible until the system is restarted. Out of 21 SSDs tested, 12 demonstrated this behavior, and one, the Western Digital SA510 2TB, could not be recovered at all. In some cases, restarting the system made the drives accessible again, but others remained unusable even after a reboot.
According to early findings, SSDs without DRAM from Phison seem to have a higher chance of problems under smaller write loads. Some HDDs have also shown similar problems under comparable workloads.
Phison is working with Microsoft and other partners to address the issue, according to a statement sent to BleepingComputer by a Phison spokesperson:
Phison has recently been made aware of the industry-wide effects of the ‘KB5063878’ and ‘KB5062660’ updates on Windows 11 that potentially impacted several storage devices, including some supported by Phison. We understand the disruption this may have caused and promptly engaged industry stakeholders. At this time, the controllers that may have been affected are under review, and we are working with partners.
Microsoft has not yet commented publicly on the issue.