Hi,
there is no notification neither processorLayoutsChanged() nor numChannelsChanged() when both, input and output are switched to << none >> from the Audio/MIDI Settings dialog, there are also no notifications on Application start.
How is this supposed to configure the plugin in this case?
… and moreover all notification at startup return nullptr for StandalonePluginHolder::getInstance() because all are called from its constructor, which means that neither AudioDeviceManager nor an AudioIODevice is available.