In August 2025, a cumulative update labeled KB5063878 that Microsoft released for Windows 11 24H2 accidentally caused a widespread hardware failure crisis. Although the update was intended to fix security issues and improve gaming performance, some users experienced abnormal solid-state drive failures during large file transfers, including cases where drives became unrecognizable and data was lost.
The issue was first noticed by Japanese gamers updating Cyberpunk 2077. Multiple users reported that when transferring more than 50GB of data at once, their systems suddenly showed errors: File Explorer froze or crashed, and afterward, the SSD completely “disappeared” from the system. The tech community confirmed that this problem occurs most often when the drive is more than 60% full and handling continuous, large write operations.
Users reported different levels of problems. Minor issues included trouble reading the drive’s health data (SMART information) and input/output errors, which usually fixed themselves after a restart. More serious cases left the SSD totally unrecognizable by the system, with damaged partition tables or file systems. The disk showed up as RAW format, meaning the data was unreadable and likely lost forever.
The problem affected many well-known SSD brands. User reports indicated that drives from companies like Corsair, Kioxia, SanDisk, and ADATA all experienced similar failures. Technical analysis showed that although SSDs using Phison controllers were mentioned most often, drives with other controllers were also affected.
Technical experts believe the problem may be due to changes Microsoft made to how Windows handles write operations. During heavy, continuous writing, the new buffering method might conflict with the SSD controller’s garbage collection process. This could cause the write request queue to grow abnormally large, overloading or resetting the controller.
Microsoft has officially acknowledged the reports and said it is working with hardware partners to investigate. However, the company has not yet released an official fix. Phison Electronics released a statement admitting the problem has “industry-wide impact” but emphasized that it is not only affecting their products. The company also denied the authenticity of a so-called “internal document” circulating online, calling it fake and stating that legal action has been taken.
Due to the seriousness of the situation, tech experts advise users to take steps to protect themselves. Users who haven’t installed the update should pause the installation. Those who have already installed it should avoid moving or writing very large files, especially avoiding continuous writes of over 50GB when the drive is already fairly full. Most importantly, users should back up important data to cloud storage or an external drive immediately.
This event serves as an important reminder to all computer users: regular data backups are the most important safety practice in the digital age. While waiting for an official solution, users should keep an eye on announcements from Microsoft and hardware manufacturers to avoid irreversible data loss caused by a system update.
