AUv2 wrapped plugins crash in SDK version 3.7.7


The current version of the AUv2 wrapper seems to be broken. The relevant code in the render function is line 1365 in, i.e.

input->IsActive () ? (Sample32*)input->GetBufferList ().mBuffers[channel].mData : 0;

input->IsActive () is always false and thus all the inputs are filled with NULL pointers, which are passed on to the plugin’s process function. In case of the output buffers it works. The code here hasn’t changed so I assume it has to do something with the way the buffers are initialized.

This can easily be reproduced with the again_au example and happens regardless of the host I’m using (tested in Logic and REAPER at least, auval fails, too). 100% reproducible, simply load up your DAW, create a track and fire up again_au → instant crash. Here’s the relevant portion of the callstack of the crashed thread:

Thread 18 Crashed:
0   com.steinberg.vst3.again      	0x0000000116574cc1 float Steinberg::Vst::AGain::processAudio<float>(float**, float**, int, int, float) + 129 (againprocess.h:61)
1   com.steinberg.vst3.again      	0x000000011657490d Steinberg::Vst::AGain::process(Steinberg::Vst::ProcessData&) + 1549 (again.cpp:288)
2   com.steinberg.vst3plugin.again.audiounit	0x0000000107d3596b Steinberg::Vst::AUWrapper::Render(unsigned int&, AudioTimeStamp const&, unsigned int) + 811 (
3   com.steinberg.vst3plugin.again.audiounit	0x0000000107d21fe0 AUBase::RenderBus(unsigned int&, AudioTimeStamp const&, unsigned int, unsigned int) + 96 (AUBase.h:319)
4   com.steinberg.vst3plugin.again.audiounit	0x0000000107d18059 AUBase::DoRenderBus(unsigned int&, AudioTimeStamp const&, unsigned int, AUOutputElement*, unsigned int, AudioBufferList&) + 185 (AUBase.h:786)
5   com.steinberg.vst3plugin.again.audiounit	0x0000000107d17959 AUBase::DoRender(unsigned int&, AudioTimeStamp const&, unsigned int, unsigned int, AudioBufferList&) + 1081 (AUBase.cpp:1406)
6   com.steinberg.vst3plugin.again.audiounit	0x0000000107d1c5b5 AUMethodRender(void*, unsigned int*, AudioTimeStamp const*, unsigned int, unsigned int, AudioBufferList*) + 133 (AUPlugInDispatch.cpp:274)
7   com.cockos.reaper             	0x0000000100540fbb AU_Plugin::ProcessSamples(double*, int, int, int, int, double, MIDI_eventlist*, double, double, bool) + 5307

Please fix this ASAP.

EDIT: I have added an issue on GitHub AUv2 Wrapper crashes in V3.7.7 · Issue #107 · steinbergmedia/vst3sdk · GitHub


Hey Rey,
sorry for the inconvenience the bug is a result of a merge issue.
You can fix this locally until we provide a fix by removing 4 lines starting at
line 2580 in the auwrapper code.


Hi Arne,

Thanks, that does the trick!