Microsoft has rejected claims that the August 2025 Windows 11 update (KB5063878) caused SSD failures, stating they could not reproduce the issue. Reports primarily from Japanese users noted that SSDs over 60% full experienced corruption during large file operations. Controller-maker Phison confirmed they also found no link and recommended users with such drives avoid heavy file usage. The root cause of these failures remains unidentified, impacting users across brands like Corsair and Maxio.