Skip to main content

Message: "Failed opening MIDI system" on startup (Win7/64)

Author housekeeper

If your startup log reads like this, there is probably a conflict with the ASIO4ALL driver under Windows 7 64bit:

Linking to external MIDI libraries
exception occured #(3221225477 0)
Failed opening MIDI system [exception occured #(3221225477 0)]
Failed opening MIDI system [error: 2]. Possibly built-in GS Wavetable Synth is blocked from using your audio driver. 

You might need to disable the internal Microsoft GS Wavetable Synth, which attempts to use the driver. The current release of ASIO4ALL can only serve a single client (synth, DAW) at a time, so if you have a DAW running, HN2/Synfire Pro can not start if the synth is still enabled. Here's a forum post that discusses how to disable the GS synth:



Mon, 2011-11-14 - 17:48 Permalink

I have tried the methods in the link with no solution. I am not using ASIO4ALL driver but the M-Audio driver that comes my interface. OS system is Windows 7 svc pck 1. Ironically I downloaded ASIO4ALL thinking the issue was with M-Audio driver, but having read this at least that confusion is resolved. Any suggestions appreciated.

Mon, 2011-11-14 - 18:49 Permalink

Well dont know if anyone is reading these but if it helps a little then that's fine. I found out that if you disable the Internal Wavetable from routing with Microsoft GS wavetable  synth in the routing section of HN2  (which is automatically done)  you are then able to ( after closing HN 2 of course) open your stand alone vst (and DAW) first without receiving the Midi error and HN 2 closing after that.


You will get some sort of error stating that a sound device (not exact wording) is required and to go the routing section of the program to address, but you are still able to open successfully.


My only issue is my stand alone doesn't appear in the device description for me to connect. So, if anyone can help me I would appreciate it. Thnx..

Mon, 2011-11-14 - 19:00 Permalink

My only issue is my stand alone doesn't appear in the device description for me to connect.

It can't. A simple MIDI connection cannot tell anything about the devices installed on your computer. You need to create a device description (Device >> New) and add the sounds to it that you want to use. That's easy, if it follows the GM standard: Just add a new sound bank and make Bank >> Initialize GM. If it's another sound library or synth, you will need to add each sound individually:

  1. Name
  2. Channel (if it is on a fixed channel)
  3. Program (if it is selected by a MIDI program change message)
  4. Category (so HN2 knows how to play it)
  5. Playing Ranges (ditto)

This is a bit of work but when you're done, you can use that device again and again for your songs.

BTW: Here's some mroe info rearding the ASIO issue:



Mon, 2011-11-14 - 21:04 Permalink

Thanxs for the speedy response. I'm using Sonik Synth 2. I already read on the "direct adressing" which kind of seems a lot easier seeing as the method mentioned in the first section needs GM method. I don't believe this vst does (unless I'm wrong). The direct adressing  along with disabling the need for HN 2 to automatically route using the GS has allowed me to "side-step" the  Midi error issue. I have tried and it appears to work from my lap top. I will take a look at the link to see if there's any information useful.

Will post if any issues.

Tue, 2011-11-15 - 04:26 Permalink

I looked at the link and pretty much it's just customers arguing with Microsoft "engineers". The engineers are blaming the issue on ASIO4ALL and posting a link on their webite to ASIO4ALL when the questions being posed to them was "how to disable GS Wavetable."  Any "solutions" came from consumers trying to post complicated "work arounds" to  help  other who posted but got no answer or where given an ASIO4ALL link.


The "fix" i mentioned earlier apparently doent work with DAW's. I've tried opening the DAW last and HN2 first and visa versa. Either HN2 crashes or the there no sound coming from any of the vsts in the daw. I also don't have use of my midi controller in the daw, just in HN 2 (advanced).


Not being an software engineer by any stretch it seems the issue is fairly straight forward. HN2 Advanced is asking for a GM synth on set up, which in turn  "if connected" uses the same driver required by the vst or vsts located in the DAW. These drivers (and I am not using ASIO4ALL by the way. I have both but choose MAudio's) cannot not  service both .


This is a loop that will not be broken unless HN2 does not require use of synth "automatically" or by default. As I stated I was able to break that chain by opening HN2 "deslecting" the routing (request) being made by HN2 for the GS Wavetable synth. I understand it's defaulted for giving the program sounds initally but it seems to be "in the way".  This trick does not work using Cubase, just Sonik Synth 2 as a stand-alone.  When I manage to  have both programs up without HN 2 freezing and crashing, my midi controller is hostage to HN 2- rendering it useless in the DAW.


I have looked over all the threads posted and visited the 2 links. The links aren't that helpful, the people in one are "good intentioned" but are doing a bit of guessing, and the other as I stated have engineers that are have less answer then the consumers posting. They are just passing the buck.


Appreciate any suggestions. Thank u.


If there's something I'm missing  then



Tue, 2011-11-15 - 10:19 Permalink

This issue seems to happen only with certain ASIO drivers. It did not occur before Vista. We are very annoyed by this and as a result, we have rewritten the entire MIDI layer of HN2 already. The next version of HN2 will be better prepared against this issue.

Note that the problem only occurs when the wavetable synth wants to play on your ASIO-driven hardware. If there is any way to make it use other sound hardware, the issue is gone:

  • Some guy suggested to put a cheap $10 soundcard in your PC and configure Windows to use it for system sound output. Haven't tested this, but it seems logical to me.
  • You may also have luck with enabling an onboard sound chip on your motherboard, and use that for system output.

The key is to keep the wavetable synth away from your ASIO hardware.

Also note that this issue is hard to work around because once HN2 attempts to get a list of the available MIDI ports, the wavetable synth already seems to be activated.