Why the Windows 11 KB5063878 Update Can Cause SSD “Drop‑Disk” Failures

In mid‑August, Microsoft released the KB5063878 update for Windows 11 24H2 (internal version 26100.4946), primarily to address security vulnerabilities and add new features.

Shortly after deployment, users reported severe hardware issues: the update could cause solid‑state drives (SSD) and mechanical hard drives (HDD) to fail, often referred to as “drop‑disk” problems. The issue also affected Windows 11 23H2 and Windows 10 users.

Relevant update identifiers are:

Windows 10: KB5063709, KB5063877, KB5063871, KB5063889

Windows 11: KB5063878, KB5063875

The problem was first discovered by an external user, @Necoru_cat, who noticed that after installing KB5063878 while patching Cyberpunk 2077 , the SSD used for the game became unrecognizable by the system.

Testing showed that writing more than 50 GB of data with SSD controller utilization over 60 % triggers the failure, and the SMART information becomes unreadable. Even after a reboot the drive may temporarily reappear, but further heavy writes cause repeated failures and risk data corruption.

Particularly vulnerable SSD models include:

Corsair Force MP600

Phison PS5012‑E12 series

KIOXIA EXCERIA PLUS G4

Fikwot FN955

Samsung (various) NVMe 3D SSDs

InnoGrit‑controlled SSDs

Maxio SSDs

KIOXIA M.2 SSDs

Further tests revealed two failure levels: NG Lv.1 – the SSD disappears during write operations but can be recovered after a reboot; NG Lv.2 – the SSD remains undetectable even after reboot, effectively “bricked.” For example, Western Digital SA510 was reported as permanently damaged.

The issue has not been globally verified, and neither Microsoft nor the SSD manufacturers have issued an official response.

Users are advised to uninstall the KB5063878 update (and related patches) before performing large, sustained write operations. The removal steps are: open Settings → Windows Update → Update History → Uninstall updates, locate the KB number, uninstall, and restart the system.

Regardless of the update status, regular data backups are strongly recommended, following the 3‑2‑1 rule (three copies, two media types, one off‑site).