1 Topic by thx538 (edited by thx538 2026-03-11 08:00:43)

  • Registered: 2026-03-10
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Topic: RME ARC connection is broken after Windows Midi Services installation

Good morning,
I have reported the bug below to Windows Midi Service on Github, but I wanted to post here as well for you to know,
and also as there may be a workaround or a configuration to be set somewhere.

Device: RME UCX + RME ARC, TotalMixFx v1.99 with latest firmware

Thanks for your help.




Windows Version Windows 11 25H2 Build 26200.7840
Service Installation Method : KB5077241

Application using WinMM MIDI 1.0 (Classic API)
Type of bug : Application not working as expected

When i connect an RME ARC device, all buttons flash once as expected, however, only the talkback and dim buttons remain lit but dimmed, which indicates a potential issue with the connection or configuration.
I have tried different connection with different usb ports and even changing the cable with no effect.
The only effective workaround i could find is to deactivate and reactivate the ARC device in windows device manager each time the device is connected.

Expected behavior :
When i connect an RME ARC device, all buttons should flash once as expected and some buttons should be lit (not dimmed) according to RME Totalmix application settings (ARC USB Settings).

Additional notes :
Checked with midicheckservice.exe :

  • The new stack is installed with KB507724.

  • Uninstalling KB507724 fixes the problem.

  • waedi
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Re: RME ARC connection is broken after Windows Midi Services installation

then no help needed, right ?

What was the reason to install KB507724 ?
was there a benefit ?

M1-Tahoe, Madiface Pro, Digiface USB, Babyface silver and blue

3 Reply by vinark (edited by vinark 2026-03-10 21:28:30)

  • vinark
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Re: RME ARC connection is broken after Windows Midi Services installation

It is the new midi 2.0 stack and installed with windows 11 automatic updates (not available nor will it ever be for win10). It causes all kind of problems with older midi devices, but should improve midi with correctly working ones..

Vincent, Amsterdam
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  • vinark
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Re: RME ARC connection is broken after Windows Midi Services installation

https://discord.com/invite/NNJgpDuYNe
Discord by MS about the new midi 2.0 stack and bugs.

Vincent, Amsterdam
https://soundcloud.com/thesecretworld
BFpro fs, 2X HDSP9652 ADI-8AE, 2X HDSP9632
  • mkok
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Re: RME ARC connection is broken after Windows Midi Services installation

It’s all over the Cubase forum as it’s causing loads of problems. There is a windows fix for it as it’s not an RME bug. See vinark’s link.

Babyface Pro Fs, Behringer ADA8200, win 11 PCs, Cubase/Wavelab, Adam A7X monitors.

6 Reply by thx538 (edited by thx538 2026-03-11 08:01:01)

  • Registered: 2026-03-10
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Re: RME ARC connection is broken after Windows Midi Services installation

waedi wrote:

What was the reason to install KB507724 ?
was there a benefit ?

KB5077241 is an optional preview and I wanted to make a quick test.
The main benefit (for me) is MIDI device sharing across applications, and there is also a built-in loopback capability which could be interesting.
In any case the new MIDI stack will be included in regular (gradual rollout) Windows 11 updates if you apply them, which I do.

waedi wrote:

then no help needed, right ?

Not exactly right.
In fact I don't use MIDI with my UCX and  I was hoping a workaround could be found with some given TotalMix settings or ARC USB settings.

mkok wrote:

There is a windows fix for it as it’s not an RME bug.

I would love this to be true :-)
I did not see any fix yet and it may take monthes.
So given the new midi stack deployment policy the bug will reach me (and others) one day or another.

7 Reply by ramses (edited by ramses 2026-03-11 09:41:32)

  • ramses
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Re: RME ARC connection is broken after Windows Midi Services installation

I would recommend delaying updates not to get bad patches in.

https://forum.rme-audio.de/viewtopic.php?id=43086

BR Ramses - HDSPe MADI FX, M-1620 Pro D, 12Mic, UFX III, ADI-2 Pro FS R BE, Nuendo 15, Win10 IoT Ent
  • Registered: 2023-02-27
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Re: RME ARC connection is broken after Windows Midi Services installation

Have you tried this fix?
https://github.com/microsoft/MIDI/relea … estamp-fix

I'm not sure if this can solve the problem. Based on the general bug phenomenon: "no notes are played on the virtual instrument (due to timestamps being far in the future)", I think it might be worth a try.

  • Registered: 2026-03-10
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Re: RME ARC connection is broken after Windows Midi Services installation

ramses wrote:

I would recommend delaying updates not to get bad patches in.

https://forum.rme-audio.de/viewtopic.php?id=43086

Thank you for the advice, but I would rather avoid such a solution.

10 Reply by thx538 (edited by thx538 2026-03-11 12:13:14)

  • Registered: 2026-03-10
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Re: RME ARC connection is broken after Windows Midi Services installation

OHtaru wrote:

Have you tried this fix?
https://github.com/microsoft/MIDI/relea … estamp-fix

I'm not sure if this can solve the problem. Based on the general bug phenomenon: "no notes are played on the virtual instrument (due to timestamps being far in the future)", I think it might be worth a try.

I did try, but with no effect.

In the meantime the new MIDI stack is now permanently installed with the latest Windows update (KB5079473), and I have W11 25H2 build 26200.8037.

I'm curious to know if anyone having the same build is experiencing the issue (talkback and dim buttons lit but dimmed when disconnecting and reconnecting the ARC).

The only workaround i could find are either (when in "dimmed" state) :

  • deactivating and reactivating the ARC device in windows devices manager

  • exiting and restarting totalmix

  • ramses
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Re: RME ARC connection is broken after Windows Midi Services installation

thx538 wrote:
ramses wrote:

I would recommend delaying updates not to get bad patches in.

https://forum.rme-audio.de/viewtopic.php?id=43086

Thank you for the advice, but I would rather avoid such a solution.

Now I am interested, why?

BR Ramses - HDSPe MADI FX, M-1620 Pro D, 12Mic, UFX III, ADI-2 Pro FS R BE, Nuendo 15, Win10 IoT Ent

12 Reply by thx538 (edited by thx538 2026-03-11 12:02:07)

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Re: RME ARC connection is broken after Windows Midi Services installation

i prefer to receive security updates ASAP, and also it is difficult to chase bugs when you don't have the latest patches.
And also, in my case, I'm quite interested in the MIDI device sharing across applications

13 Reply by ramses (edited by ramses 2026-03-11 12:14:22)

  • ramses
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Re: RME ARC connection is broken after Windows Midi Services installation

thx538 wrote:

i prefer to receive security updates ASAP, and also it is difficult to chase bugs when you don't have the latest patches.
And also, in my case, I'm quite interested in the MIDI device sharing across applications

I am fully with you. But experience shows that Microsoft very often f*s things up, especially with Windows 11.
Therefore, I would prefer and recommend to delay at least for a week.

If you have a well-worked-out backup procedure that does its job reliably within ~10-15 minutes,
then you are fine not to delay updates, if you are willed - for whatever reason - to take the risk.

We also know that many people are not good at administering their systems when it comes to system backup and restore.
I think especially in those cases, delaying updates brings more stability in.

BR Ramses - HDSPe MADI FX, M-1620 Pro D, 12Mic, UFX III, ADI-2 Pro FS R BE, Nuendo 15, Win10 IoT Ent
  • Registered: 2022-10-26
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Re: RME ARC connection is broken after Windows Midi Services installation

Perhaps post here. There’s a very helpful MS person in that thread.
https://gearspace.com/board/music-compu … nfo-4.html

  • mkok
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Re: RME ARC connection is broken after Windows Midi Services installation

It may be the same person who is in the Cubase forum thread. There is a solution on that thread. For what I use I’m not seeing the problem. It may be your only solution.

Babyface Pro Fs, Behringer ADA8200, win 11 PCs, Cubase/Wavelab, Adam A7X monitors.
  • Registered: 2026-03-10
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Re: RME ARC connection is broken after Windows Midi Services installation

mkok wrote:

There is a solution on that thread.

Thank you, but where is the thread and the solution ?

17 Reply by mrkahuna (edited by mrkahuna 2026-03-11 18:01:59)

  • Registered: 2022-10-26
  • Posts: 77

Re: RME ARC connection is broken after Windows Midi Services installation

Go here: https://devblogs.microsoft.com/windows- … -february)

This sounds like your issue?  The linked GitHub issue says the fix should be rolling out.

"Apps using the WinMM MIDI 1.0 API may not see newly plugged-in devices."
Does the RME software use that Api?

  • Registered: 2026-03-10
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Re: RME ARC connection is broken after Windows Midi Services installation

mrkahuna wrote:

Go here: https://devblogs.microsoft.com/windows- … -february)

This sounds like your issue?  The linked GitHub issue says the fix should be rolling out.

"Apps using the WinMM MIDI 1.0 API may not see newly plugged-in devices."
Does the RME software use that Api?

I hope this it .... thanks for the reference.
I'll wait and see.

Thanks all for your kind support.

19 Reply by The Elf (edited by The Elf 2026-03-27 15:18:00)

  • Registered: 2018-04-16
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Re: RME ARC connection is broken after Windows Midi Services installation

I'm hitting this problem since the new MIDI stack arrived. My PC can see the RME ARC in Device Manager, and it is listed in the MIDI services app, but it never connects to TotalMix.

  • Registered: 2026-03-10
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Re: RME ARC connection is broken after Windows Midi Services installation

Have you tried to stop and restart TotalMix? or (less reliable) deactivate and reactivate the ARC in the Device Manager.

21 Reply by The Elf (edited by The Elf 2026-03-27 16:31:30)

  • Registered: 2018-04-16
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Re: RME ARC connection is broken after Windows Midi Services installation

Thanks for the response.

Re-starting TotalMix just now did seem to fix it. Disabling/enabling the ARC in Device Manager doesn't have any effect.

I'll try the re-start of TotalMix for a few days and see if this is a temporary workaround I can rely on.

  • Registered: 2007-05-02
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Re: RME ARC connection is broken after Windows Midi Services installation

Same problem here. Boot computer, everything OK, load up Cubase and do some work. Quit Cubase and ARC stops working. Unplug and replug has no effect. Restarting Windows Midi service does nothing. I can see it in device manager, changed everything in Total Mix, but no joy as Total Mix can't see it anyway, there's no yellow lights on ARC.

Will try a reboot and just leave Cubase open all the time and hopefully that will be a workaround for now.

23 Reply by MC

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Re: RME ARC connection is broken after Windows Midi Services installation

Try the latest beta from TotalMix forum. Also 'no yellow lights' would mean the USB cable is not plugged in or power on USB is off. That would be a totally different thing then.

Regards
Matthias Carstens
RME

MC's Website

24 Reply by The Elf (edited by The Elf 2026-04-17 16:42:35)

  • Registered: 2018-04-16
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Re: RME ARC connection is broken after Windows Midi Services installation

I can confirm that restarting TotalMix after unplugging/re-plugging my ARC usually fixes the problem. I have created my own kill/re-start of TM from a batch file.

I don't let beta software near my PC, so I will wait until a new version of TM arrives as a stable release.

25 Reply by MC

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Re: RME ARC connection is broken after Windows Midi Services installation

TM FX 2.0/1.991 is no longer beta.

Regards
Matthias Carstens
RME

MC's Website

26 Reply by thx538 (edited by thx538 2026-05-19 06:01:33)

  • Registered: 2026-03-10
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Re: RME ARC connection is broken after Windows Midi Services installation

The issue seems fixed here with TotalMix v2.01 (and W11 build 26200.8457).
Have a nice day.