Trouble with the Owlsim in Audacity on MacOS

I’m trying to use the pre-built binaries of the Owlsim with Audacity (2.0.3) on MacOS
but none of them works. The Owl interface shows upp after I’ve chosen either version in the effects-menu but I’m locked out and can’t click or move anything apart from the preview-, cancel- or OK-button at the bottom. I’ve managed to get both the AU- and the VST-version working in the trial-version of Reaper so it’s an Audacity-related problem.

Seems like Audacity does not support VST-plugins that need to be open during processing. I assume that’s the case with the Owlsim.

Why do some VST plug-ins not work or display incorrectly?

Audacity will by default display VST effect plug-ins with a full graphical interface where the plug-in supplies this. Any plug-in that requires to be left open while processing audio will not work correctly. VST instrument (VSTi) plug-ins are not currently supported.

If any plug-in displays incorrectly, you can uncheck “Display VST effects in graphical mode” in the Effects Preferences to display a simpler tabular interface for the plug-in (this also affects all other plug-ins).

I’ve just tried the same thing, and it seems that unchecking “Display VST effects in graphical mode” does make a difference. I don’t know why.

Audacity has a really strange way of dealing with VST though! And I’m not sure exactly what they mean with ‘requires to be left open while processing audio’.
It appears as if the message thread is halted, or not started, the way that the GUI is displayed but not receiving mouse events. Or perhaps there’s a deadlock issue. I’ll have a look with a debugger when I have a bit more time.

Here’s a discussion on the Juce forum with similar problems: