# VST3 /JUCE layout conversion error

**URL:** <https://forum.juce.com/t/vst3-juce-layout-conversion-error/54715>\
**Category:** Audio Plugins\
**Created:** [January 26, 2023, 3:15pm UTC](https://forum.juce.com/t/vst3-juce-layout-conversion-error/54715 "2023-01-26T15:15:31Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![lalala](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/lalala/32/8577_2.png) [@lalala](https://forum.juce.com/u/lalala)\
**Post date:** [January 26, 2023, 3:15pm UTC](https://forum.juce.com/t/vst3-juce-layout-conversion-error/54715/1 "2023-01-26T15:15:31Z")

</div>

latest dev tip, I’ve got this assertion triggered in getChannelSetForSpeakerArrangement():

```auto
// VST3 <-> JUCE layout conversion error: report this bug to the JUCE forum
    jassertfalse;

```

to reproduce:

- create a basic plugin project with the projucer
- in the projucer, set the `Plugin Channel configurations` to `{2, 2}, {1, 2}`

build and run in reaper on mac

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<div class="post-metadata">

**Author:** ![reuk](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/reuk/32/21494_2.png) [@reuk](https://forum.juce.com/u/reuk)\
**Post date:** [January 26, 2023, 5:39pm UTC](https://forum.juce.com/t/vst3-juce-layout-conversion-error/54715/2 "2023-01-26T17:39:59Z")

</div>

Thanks for reporting. I think that comment might be misplaced - it looks like in this case, REAPER is trying to enable all 64 possible speakers, but there’s no way of representing that layout in JUCE at the moment.

Either this case shouldn’t assert, or the warning should be moved to `setBusArrangements` in the plugin client code, to warn that the host has requested a layout that JUCE can’t use. I’ll have a think and update this thread once we’ve pushed a fix.

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<div class="post-metadata">

**Author:** ![reuk](https://sea2.discourse-cdn.com/flex026/user_avatar/forum.juce.com/reuk/32/21494_2.png) [@reuk](https://forum.juce.com/u/reuk)\
**Post date:** [January 26, 2023, 7:40pm UTC](https://forum.juce.com/t/vst3-juce-layout-conversion-error/54715/3 "2023-01-26T19:40:17Z")

</div>

> <https://github.com/juce-framework/JUCE/commit/39ba1c838307d66f0c99598d2b006b16fecc587c>
>
> Some hosts (e.g. REAPER) will attempt to instantiate plug-ins with 64
> active cha…nnels, and JUCE can't represent this layout. In this case,
> failing to convert between VST3/JUCE layouts is not a logical error, so
> asserting is not appropriate.