Following the release of the Windows 11 version 24H2 KB5063878 security update on August 12, 2025, a critical issue has been reported by users. After installing this update, some computers have experienced SSD and HDD drives disappearing from the operating system, with files being deleted and data becoming unrecoverable. Although Microsoft has stated that the issue is not widespread, the number of affected users has continued to grow after moving to this version. Conditions under which the issue occurs: When writing large amounts of data (over 50GB) When the SSD or HDD is more than 60% full Drives potentially at risk: Corsair Force MP600 SSDs using the Phison PS5012-E12 controller KIOXIA EXCERIA PLUS G4 / KIOXIA M.2 SSDs Fikwot FN955 SSDs using InnoGrit controllers Maxio SSDs SanDisk Extreme Pro 3D Microsoft’s statement: Microsoft has confirmed awareness of the reports: “We are aware of these issues and are working with our partners to investigate,” the company said. However, no official fix has yet been released. How to Protect Yourself Pause Updates If you have not yet installed KB5063878, it is strongly advised to pause Windows Updates until an official fix or patch is released. Back Up Your Data Due to the risk of data loss and drive corruption, all critical files should be backed up to external storage or cloud services. Uninstall the Update If you have already installed KB5063878 and are experiencing issues, it is recommended to uninstall the update or roll back to a previous version.