Unit1. and RootUnit. decoration VST2 Wrapper, Default GUI in some clients


VST3SDK 3.6.6

I’ve been having an issue for some time that is repeatable with the AGain sample plugin in the SDK.

When using the VST2 wrapper and using the plugin as a VST2, in some clients (notably Ableton Live, both Win and MacOS) the Default/Client GUI controls show the parameter names decorated with “Unit1.” or “RootUnit.” The image below shows the AGain sample plugin in Ableton:
Screen Shot 2016-11-30 at 4.51.21 PM.png
I have found that I can eliminate this string decoration by using:


when initializing the parameter objects.

The problem is that with this “fix” in place, the Plugin will fail the VSTValidator software (and potentially be rejected in some clients in the future that may rely on that validation as a test before loading?).

Is there a recommended way of handling this so that the name decoration does not occur, and the plugin will still pass the VSTValidator software?

The problem does not occur in Cubase 7 or 8. It did occur in previous versions of Reaper, but appears to now be fixed. As such, it seems to be a host-side issue. However, as it occurs in Ableton Live, which has been a longtime and favored VST2 host, I would like to know if there is a fix on the plugin side.

Thanks as always,


you can control this behaviour on line 69 of vst2wrapper.cpp of the SDK:

bool vst2WrapperFullParameterPath = true;


Thank you, Arne!