Unable to init ryzenadj on Windows 11 25H2 (build 26200.8655) - WinRing0x64 blocked, cause unknown

[tavdiego]

Device: Medion E15302
CPU: AMD Ryzen 5 3500U with Radeon Vega Mobile Gfx
OS: Windows 11 25H2 (Build 26200.8655)
RyzenAdj version: v0.14.0 (win64)

Problem:
RyzenAdj stopped working after Windows Update KB5094126 was installed on 12/06/2026. Before this update, RyzenAdj was working perfectly and successfully setting STAPM/PPT limits.

Error message:

Unable to get os_access Obj, check permission
Unable to init ryzenadj

What I tried:

• Running as Administrator ✓
• Disabling Secure Boot in BIOS ✓
• Disabling AMD External Events Utility service ✓
• Running bcdedit /set hypervisorlaunchtype off ✓
• Uninstalling KB5094126 ✓
• Using UxTU as alternative (same result, STAPM stays locked at 12W)

HWiNFO confirms:

• APU STAPM = 12.000W (locked, never changes)
• APU STAPM Limit = 100% permanently
• No thermal throttling (HTC = No)

bcdedit /enum output: Secure Boot was disabled, hypervisorlaunchtype set to off, no testsigning available.

Is there a known fix or workaround for Windows 11 25H2 build 26200.8655? Could WinRing0x64.sys be blocked by a new kernel security policy introduced in this update?

Thank you.