I would suggest posting more logs if there are any (check system logs). Where did that error come from?
This is a reference to the official (core) Z-Wave JS add-on,
but then you say you are using Z-Wave JS UI. Something in your installation is still referencing the official add-on. You can’t use both add-ons at the same time. Make sure this is not the case. You can easily verify which add-on is being used by the integration by looking at the Server URL in the integration configuration. The error message seems to indicate the add-on is not installed, but something is referencing it.
If the URL points to core-zwave-js, then you need to fix it by following the guides:
- https://www.home-assistant.io/integrations/zwave_js/#can-i-switch-between-the-official-z-wave-js-add-on-and-the-z-wave-js-ui-add-on
- Switching Z-Wave JS Addons with Minimal Downtime! Z-Wave JS (Official) to Z-Wave JS UI (Community)
If the Server URL points to the ZUI add-on, then something else is going on and we’ll probably need more logs or information.