Warning! Windows Security Update KB405689# blocks M-PC output!


Hello Everyone,

As from yesterday, 07.01.2018, please notify, that latest MS Windows Update KB405689# (last number may vary, according to Windows build), will block M-PC outputs

The above seems to be relevant, to all M-PC devices:

  • M2PC
  • M-Touch
  • M-Play
  • M-DMX
  • ArtNet devices

First, disable Windows Update. Otherwise, Windows will try to reinstall any removed updates

  • Go to Advanced options, and enable Pause Updates

Next, remove KB405689# update file

  • Click the Windows icon, and click the Settings icon

  • Click Update & Security:

  • Click the View installed update history option

  • Click the Uninstall updates option:

  • Right click the KB405689# item, from Microsoft Windows list, to uninstall

M-PC not working after Windows 10 Updates
M-PC on Windows 7 SP1
MIDI Timecode in doesn't work in M-PC.
M-PC not working after Windows 10 Updates
M-Touch DMX output 'stuck'
Smart Show NetDMXII - Wont Come Up in MPC
USB to DMX not working with M-PC (mid load-in)
M-PC not sending DMX out of M-Touch, but works when using "Console Tester"
M2PC and M-Play not sending data


I believe that Update KB4056891 is doing the same but on a smaller scale.


are you guys planning a patch for this?


I read of this alternative. It’s a registry tweak to disable the update instead of uninstalling it. I wonder if it would fix the problem.


Maybe a nice workaround ?

Thanks @Matthias


Workaround Testing:

I will update this post as I go.

DISCLAIMER: I am NOT working for MARTIN, Harman or Samsung. Asking me about anything these companies do or don’t is useless.

System: Lenovo Yoga i7, 8 GB RAM Windows 10
Artnet: MA NPU II
Martin USB-DMX Duo (grey)
Martin M-PC Beta 945

Prepatch: DMX Duo and Artnet working as intended.

Installed the Windows Patch. Artnet and USB-DMX-Duo stopped working at all.
The USB-DMX Duo is still recognized in MPC and the LEDs are still working, yet no output.

Test 1: The Workaround mentioned by Sylvain a few posts above, and found under https://www.theastrogeek.com/dark_sky_journal/microsoft-windows-10-security-update-causes-ascom-drivers-to-crash/1/2018

Found the following entries in DCOMCNFG:


put them all to “call” - still no DMX Output.

Reverted back to before the patch since I do need it working now. More testing once I got more info.

Additional information: Microsoft admitted breaking several things with the patch and promised an solution.



Thanks for your time and efforts, Michael!


For those of you that have Windows 10 Pro, or those that have Windows 10 home(Home version doesn’t appear to provide the Pause Update for 35 days option) follow the instructions in this article to disable Windows updates (Way #2) then remove the KB405689# update, which will restart your computer. On my computer this appears to stop the automatic updates. You can re-enable once problem is resolved.


Thank you, @mhall1138

Just had a customer calling with the same issue (W10 Home), and used that exact same method, succefully


It will not work for me - help! I have uninstalled the Windows Update (KB4056892) , but I still not get any DMX signal output in M-PC.
Are there any other things I have to do to fix the issue ?


It is not only KB4056892, but any other KB405689# updates…


I have no KB405689# updates as I can see?


You’re looking in the wrong part. Seems like your looking in the “View installed update history” on the Windows Update screen and then click “Uninstall updates”. The window your showing almost looks like Program and Features for uninstalling programs.


I fixed it. I had deleted the right Windows update files - but the configuration of the USB2DMX box in M-PC was not correct, and after a new config everything works.


Has there been any resolution to this other than uninstalling this update? I have MPC installed in quite a few venues in North America and it is causing issues.

On a few of the machines I am getting errors uninstalling the update and will not allow me to uninstall it.

On others I have uninstalled the update file and still have no DMX output.

At a loss on what to do…


@Martin_Controller where are you?

You leave us orphan since months. I’ve tried contacting you, Harman and also Samsung by email and no answer from nobody.

It is understood that majors change has been bring since the opt-in of Samsung, but we, your users, are alone without any official communication on the future of the M-series.

Please wake up quickly before to see a lot of people living you because we don’t have any visibility for tomorrow.

I don’t want to loose this M-Serie controller I love to use, this community and this approach of doing lights.

Yes, I’m complaining, and I’m thinking I’m not the only one.

Please communicate with us, even if it is just “We read you and we will come later with more infos”.


We read you and we will come later with more infos


This is a quagmire because the advice has been to make sure Windows is updated in order for M-PC to work correctly. Now the advice is to block the latest updates or it won’t work.

I have a Windows 8.1 install running beta 926 with intermittent problems. I had disabled updates months ago after having gotten it running. Could it be that Microsoft has discreetly installed security updates? There is a prompt when booting up because it has been connected to the internet. Recently I completely reinstalled M-PC but the DMX has still dropped out since.

So do I need to update all and then selectively uninstall KB405 updates?

It rather seems like I’m damned if I do and damned if I don’t.


This is how I feel with this whole mess.

The firm I work for is considering other options because of this.