Windows 11 October 2026 updates: BitLocker drives become RAW, system crashes and System Restore fails

I am reporting a serious, reproducible issue following the October 2026 Windows 11 updates.

System configuration

Windows 11 Pro 25H2, build 26200.9711 after updating

Intel Core i9-13900KF

ASUS PRIME Z790-P, BIOS 1840

Samsung 990 PRO system SSD

Multiple internal and external BitLocker-encrypted NTFS drives

What happened

I restored a complete AOMEI system image dated September 27, 2026. Following the restoration, Windows and all previously affected BitLocker-encrypted drives operated normally.

I disabled automatic Windows updates.

Nevertheless, on October 22, 2026, Windows automatically installed the following updates:

KB5127648 — Windows 11 security update

KB5127690 — .NET Framework security update

KB5130034 — .NET 8 security update

KB5130036 — .NET 10 security update

Immediately following the updates and restart, the same critical problem returned.

Technical symptoms and evidence

BitLocker volumes unlock successfully according to manage-bde.

Windows identifies the unlocked volumes as RAW instead of NTFS.

File Explorer returns "The parameter is incorrect".

Process Monitor captures CreateFile on J:\ failing with INVALID PARAMETER.

fltmc volumes reports RAW.

Read-only CHKDSK recognizes NTFS.

The affected drives are accessible through Windows PE on the same physical computer.

Multiple encrypted drives are affected.

The issue previously affected a second, independent Windows installation.

Following the updates, Windows also experienced a green-screen system crash and automatic restart.

Earlier crashes included bug checks 0x13A (KERNEL_MODE_HEAP_CORRUPTION) and 0x7E (SYSTEM_THREAD_EXCEPTION_NOT_HANDLED). Their relationship to the storage problem has not been established.

Recovery attempts

Uninstalling KB5127648 did not restore access.

Uninstalling KB5127690 also did not restore access.

Windows System Restore failed twice with an unspecified error.

Full system-image restoration had previously restored normal functionality, before the updates were installed again.

The evidence strongly links the recurrence to the update process, although the exact update or underlying interaction has not yet been isolated.

My questions and request to Microsoft

Is Microsoft investigating a possible regression affecting BitLocker-unlocked NTFS volume mounting after these October 2026 updates?

Is there a permanent fix that does not require disabling security updates?

Why were these updates installed despite automatic updates being disabled?

How can this reproducible issue and its supporting diagnostic evidence be escalated to the Windows engineering team?

This issue has caused significant disruption and temporary loss of normal access to important business data. Repeated full-system restoration is not an acceptable long-term solution.

I can provide screenshots, Process Monitor evidence, update history and crash dumps upon request.