# Assertion: 'inchannels \<= mMixMatrixCurrent.numin()'
**URL:** https://qa.fmod.com/t/assertion-inchannels-mmixmatrixcurrent-numin/14511
**Category:** FMOD Engine
**Created:** [April 1, 2019, 9:11am UTC](https://qa.fmod.com/t/assertion-inchannels-mmixmatrixcurrent-numin/14511 "2019-04-01T09:11:30Z")
**Posts on this page:** 10
**Page:** 1
### Author:  [@jossdisguise](https://qa.fmod.com/u/jossdisguise)
#### Post date: [April 1, 2019, 9:11am UTC](https://qa.fmod.com/t/assertion-inchannels-mmixmatrixcurrent-numin/14511/1 "2019-04-01T09:11:30Z")
I receive this error in the debug callback
`assertion: 'inchannels <= mMixMatrixCurrent.numin()' failed`
File and line info
`Trace : < assert c:\jk\workspace\Build __1.10__ API_Win\lowlevel_api\src\fmod_dsp_connectioni.cpp:575]`
What does it mean and how can it be resolved?
---
### Author:  [@mathew](https://qa.fmod.com/u/mathew)
#### Post date: [April 2, 2019, 10:49pm UTC](https://qa.fmod.com/t/assertion-inchannels-mmixmatrixcurrent-numin/14511/2 "2019-04-02T22:49:47Z")
You are seeing an internal consistency check fail, could you provide a way to reproduce it?
Once we know the cause we will be better positioned to recommend workarounds or action a fix.
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### Author:  [@kamyker](https://qa.fmod.com/u/kamyker)
#### Post date: [April 19, 2024, 1:53pm UTC](https://qa.fmod.com/t/assertion-inchannels-mmixmatrixcurrent-numin/14511/3 "2024-04-19T13:53:44Z")
I get this in Unity too, is there a way to get more logs?
```auto
[FMOD] assert : assertion: 'inchannels <= mMixMatrixCurrent.numin()' failed
UnityEngine.Debug:LogError (object)
FMODUnity.RuntimeUtils:DebugLogError (string) (at Assets/Plugins/FMOD/src/RuntimeUtils.cs:580)
FMODUnity.RuntimeManager:DEBUG_CALLBACK (FMOD.DEBUG_FLAGS,intptr,int,intptr,intptr) (at Assets/Plugins/FMOD/src/RuntimeManager.cs:104)
```
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### Author:  [@cameron-fmod](https://qa.fmod.com/u/cameron-fmod)
#### Post date: [April 23, 2024, 3:52am UTC](https://qa.fmod.com/t/assertion-inchannels-mmixmatrixcurrent-numin/14511/4 "2024-04-23T03:52:25Z")
The [FMOD initialization settings](https://www.fmod.com/docs/2.03/unity/settings.html#initialization) in Unity have an option for changing the logging level, you can get all the FMOD logging by setting it to `Log`.
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### Author:  [@kamyker](https://qa.fmod.com/u/kamyker)
#### Post date: [September 24, 2024, 12:02pm UTC](https://qa.fmod.com/t/assertion-inchannels-mmixmatrixcurrent-numin/14511/5 "2024-09-24T12:02:00Z")
Can’t see anything related, what about you?
Seems to happen after first song is opened from file.
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### Author:  [@cameron-fmod](https://qa.fmod.com/u/cameron-fmod)
#### Post date: [October 1, 2024, 12:01am UTC](https://qa.fmod.com/t/assertion-inchannels-mmixmatrixcurrent-numin/14511/6 "2024-10-01T00:01:13Z")
Which version of FMOD for Unity are you using?
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### Author:  [@kamyker](https://qa.fmod.com/u/kamyker)
#### Post date: [October 14, 2024, 7:57pm UTC](https://qa.fmod.com/t/assertion-inchannels-mmixmatrixcurrent-numin/14511/7 "2024-10-14T19:57:54Z")
Tried (the newest as of right now) 2.02.24 and 2.02.21
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### Author:  [@cameron-fmod](https://qa.fmod.com/u/cameron-fmod)
#### Post date: [October 23, 2024, 4:19am UTC](https://qa.fmod.com/t/assertion-inchannels-mmixmatrixcurrent-numin/14511/8 "2024-10-23T04:19:42Z")
You mentioned that it ‘seems to happen after first song is opened from file’:
Is the song being played through a bank or ogg file?
Are you using any dsp effects on the song?
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### Author:  [@kamyker](https://qa.fmod.com/u/kamyker)
#### Post date: [October 23, 2024, 2:01pm UTC](https://qa.fmod.com/t/assertion-inchannels-mmixmatrixcurrent-numin/14511/9 "2024-10-23T14:01:35Z")
From file, MODE.NONBLOCKING | MODE.CREATESTREAM .
I have a dsp reading data all the time for FFT and visualization. Anything wrong here?
```
public KSDspCapture(ChannelGroup channelGroup)
{
// Assign the callback to a member variable to avoid garbage collection
readCallback = CaptureDSPReadCallback;
// Allocate a data buffer large enough for 8 channels, pin the memory to avoid garbage collection
// 8 channel * data for 8192 length
uint bufferLength;
RuntimeManager.CoreSystem.getDSPBufferSize(out bufferLength, out var _).Throw();
uint multi = (uint)math.ceil(8192f / bufferLength);
bufferLength = bufferLength * multi * 8;
buffer = new((int)bufferLength, Allocator.Persistent);
// Get a handle to this object to pass into the callback
// Define a basic DSP that receives a callback each mix to capture audio
DSP_DESCRIPTION desc = new DSP_DESCRIPTION();
desc.numinputbuffers = 1;
desc.numoutputbuffers = 1;
desc.read = readCallback;
RuntimeManager.CoreSystem.createDSP(ref desc, out captureDSP).Throw();
channelGroup.getDSP(CHANNELCONTROL_DSP_INDEX.HEAD, out var channelGroupDsp).Throw();
captureDSP.addInput(channelGroupDsp, out channelToCaptureConnection, DSPCONNECTION_TYPE.SEND_SIDECHAIN).Throw();
RuntimeManager.CoreSystem.getMasterChannelGroup(out var master).Throw();
master.getDSP(CHANNELCONTROL_DSP_INDEX.TAIL, out var masterTail).Throw(); //move this to before fader
masterTail.addInput(captureDSP, out var con, DSPCONNECTION_TYPE.SIDECHAIN);
captureDSP.setActive(true).Throw();
dspHandle = captureDSP.handle;
DspsLookup.Add(dspHandle, this);
```
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### Author:  [@cameron-fmod](https://qa.fmod.com/u/cameron-fmod)
#### Post date: [October 25, 2024, 4:59am UTC](https://qa.fmod.com/t/assertion-inchannels-mmixmatrixcurrent-numin/14511/10 "2024-10-25T04:59:24Z")
The only thing that stands out is it looks like you aren’t passing a handle through the usedata of the `FMOD.DSP_DESCRIPTION` like we do in the [DSP Capture example](https://www.fmod.com/docs/2.02/unity/examples-dsp-capture.html), although I assume your `DspsLookup` is taking care of that instead.
Are you able to trim down a project, that does the bare minimum to throw the error, which you are able to share with us? I have been unable to reproduce the issue here so far.