Ok, I’ve cleaned up the EnginePluginDemo now so that it should work correctly on Linux: https://github.com/Tracktion/tracktion_engine/commit/ffb2690c4d012a3ac325039110574084af1b29e2
I’ve tested this on Ubuntu 16.04 with the JUCE Audio Plugin Host.
I’ve also fixed the PIP so that it should build as a synth now with MIDI input without modification.
If this still isn’t working in the Elk host let me know as there might be something more subtle going on.