Error status in plugin manager (cardinal installation)

This is my first post, my apologies in advance if I break the forum’s etiquette

using ubuntu 20.04 LTS
ardour version 6.9.0
plugin in question: cardinal (

So I did something quite dumb. I downloaded the wrong binaries of cardinal (arm64 instead of x86)
copied the files over to ~/.lv2 directory and tried bringing the plugins (there are three) into ardour. It didn’t work, so I quickly corrected my mistake by downloading the proper binaries and installing per the installation instructions (ln -s $(pwd)/*.lv2 ~/.lv2/). restarted ardour and re-scanned the plugins a bunch of times. one of the Cardinal plugins errors out, the other two are fine (see image). My suspicion is that when trying to install the wrong binaries somehow it left the plugin manager in a bad state, is there a cache or anything similar that can be cleared? Perhaps it’s another issue?

thanks for reading this, and thanks in advance for any insight you might be able to provide.

The plugin manager is complaining that the ports do not match known types. Based on the name (“CV”) those are control voltage ports. Ardour supports audio ports and MIDI ports.
I would have to double check the code to be sure, but I’m 95% sure that even though CV ports use the same underlying representation as audio ports (floating point numbers), the plugin manager is flagging that those types of ports are not supported for routing within Ardour.

Confirmed there is already a feature request relating to this:
bug tracker 7886: Support for the recording/editing CV signal?