SER10 Max - KB5121003 causes BIOS/boot failure - possible BIOS/firmware issue

vfxjfb

I want to flag what appears to be a BIOS/firmware compatibility issue on the SER10 with the latest Windows 11 security update KB5121003.

My system:

Beelink: SER10 Max
Windows: 11 25H2
OS Build: 26200.7840
BIOS: V102_P8C0M0C15.09.BL
Problematic update: 2026-08 Security Update (KB5121003), which updates the system to build 26200.9168

The update installs, the machine restarts, and then it fails to boot correctly. Windows Recovery eventually rolls the update back, allowing the machine to boot again.

What concerns me is that this does not appear to be an isolated Windows installation problem.

There is already another SER10 Max user reporting essentially the exact same issue here:
https://bbs.bee-link.com/d/11938-ser10-max-windows-update-2026-08-security-update-kb5121003-issue

There is also a recent Reddit thread with multiple SER10 users reporting the same behaviour:

In that thread, users report that the machine gets stuck during boot after KB5121003 and Windows subsequently rolls the update back. One user also reports that disabling Secure Boot and Fast Boot did not resolve the problem.

Because the failure is consistently triggered by one specific Windows update, and appears to occur at the BIOS/boot stage, I don’t think reinstalling Windows is the appropriate solution. A clean Windows installation would still attempt to install KB5121003 and, based on the reports above, potentially reproduce the same problem.

Could Beelink please escalate this to the BIOS/firmware team and investigate compatibility between the SER10 BIOS and KB5121003, rather than treating this primarily as a Windows installation issue?

If a newer BIOS is available, or if a BIOS fix is being developed for this issue, please let us know.

I would also appreciate confirmation from Beelink that this issue is being tracked as a known problem, as there now appear to be multiple independent reports of the same behaviour.

Thank you!

vfxjfb

Picture of BIOS version.

Beelink CS-June

vfxjfb

Hello there,

Your machine’s BIOS version should be the lastest.

Currently, regarding the issue that SER10 cannot update the Windows patch KB5121003 or that the machine malfunctions after updating the corresponding patch, our R&D personnel are actively seeking solutions.

We will post the corresponding solution on this thread as soon as the R&D team provides it.

Thank you for your understanding and patience.

Have a nice day~

vfxjfb

Thank you for the update. And hope you find the issue.

Beelink CS-June

vfxjfb

Hello there,

You are welcome. We are happy to help you.

If we have any updates of the machine’s problem, we will let you know.

Have a nice day!

srambole

Habe genau das gleiche Problem, ich habe im Bios bei AMD - CBS - SOC Miscellaneous - Microsoft Security Levels die Option ASP fTPM Level 0 gestellt und das Update hat funktioniert!!!!
Leider habe ich die vorherige Einstellung nicht aufgeschrieben und weiß jetzt nicht welchen Level ich jetzt einstellen muss nachdem ich das Update erfolgreich installiert habe??????
LG Hans

vfxjfb

srambole
That’s interesting srambole. I can check and let you know what the bios default setting was later today when home from work.

srambole

Das wäre super! Ich habe momentan immer noch die -0- dort stehen und möchte nichts falsches eintragen!
LG Hans

vfxjfb

Beelink CS-June

You should have a look at the message from Srambole above as it seem to give you some important clues to the security update issue we’re experiencing.

vfxjfb

srambole
It was set to customized.

Beelink CS-June

vfxjfb

Hello there,

Could you please tell me if the problem has been resolved after you completed the new BIOS settings?

Have a nice day~

vfxjfb

Beelink CS-June

I haven’t tested this myself (yet). It was “Srambole” in the message above that seem to have fixed it.
Translated his message from German to English below:

“ I have exactly the same problem. In the BIOS, under AMD → CBS → SOC Miscellaneous → Microsoft Security Levels, I set the “ASP fTPM Level” option to 0, and the update worked!!!!

Unfortunately, I didn’t write down what the previous setting was, so now I don’t know which level I should set it to after successfully installing the update??????

Best regards, Hans”

vfxjfb

Beelink CS-June

I can try this tweak myself and see what happens. It should be safe to do right?

Beelink CS-June

vfxjfb

Hello there,

You can try to see if the BIOS settings recommended by Srambole can solve the problem.

If the problem still cannot be resolved, please restore the corresponding BIOS settings to the original data of your machine.

Have a nice day~

vfxjfb

Beelink CS-June

There is now a new Microsoft update available, 2026-08 Preview Update (KB5120998) (26200.9278). Unfortunately, this update also fails and crashes during the boot process, so I had to roll back the installation to get the system working again.

I then tried the tip from @srambole and changed Microsoft Security Levels, “ASP fTPM Level” option to 0 in the BIOS.
After that, the update installed successfully and the system booted normally!

Several users report that changing AMD CBS → SOC Miscellaneous → Microsoft Security Levels → ASP fTPM Level to 0 allows KB5121003 to install successfully. Can you confirm what security features are changed by Level 0, and whether this is an approved workaround? Also, what is the correct default value for the SER10 Max? Default for me was “customized”.

Beelink CS-June

vfxjfb

Hello there,

Regarding the “ASP fTPM level” issue you inquired about, our R&D team is currently unable to provide a corresponding response.

We will ask the R&D team to attempt to reproduce the solution you tried and find the answer.

Have a nice day~