Yesterday I literally switched over my PlantLink from using their hub to going through ST and had the same issue. I found a post on here (not sure where it was) pointing out that there are two Device Handlers in SmartThings for the PlantLink.
There is “Plant Link” which is what my ST hub used automatically. And there is “PlantLink”. The latter works for me and did not give me the Unexpected Error toast. I wasn’t watching my log so I can’t confirm if something else changed.
Try going into your devices, editing the PlantLink to use this other handler.
I’m not fully sure on how to force the “PlantLink” device handler vs the “Plant Link” device handler. I’m clearly missing a fundamental understanding here.
When I choose to add a new device, it automatically finds “Plant Link” and that brings me to the error during registration.
I did a search and found another handler and I’ve added KristopherKubicki/device-plantlink-direct as a device handler in the IDE. There doesn’t seem to be a way to choose this device handler. Smartthings just discovers the device when I add it and picks the device handler it wants to use. I still get the same error so I assume it is still using the other device handler.
If I attempt to add the Plantlink manually, there is only one choice under irrigation - PlantLink Soil Moisture Sensor (Oso Technologies Inc.) This also leads to that same error.
So how do I actually choose what handler I want to use from the app?
Logging in with your ST account, you can view the devices on your hub. If you click a device and view its page, you’ll see an “Edit” button at the bottom left. This lets you update some properties. In this case it’s the "Type* " that needs to change. In the drop down there should be two plant link related handlers, “Plant Link” and “PlantLink”. For me, this was set to “Plant Link” by default, and changing to the “PlantLink” allowed the connector to work without the ‘unexpected error’
I tried to grab some screenshots, hopefully it helps:
No problem! There’s a ton of powerful and cool stuff just tucked slightly out of the way. Currently I’m exploring webCoRE. My plant can control things now based on moisture reading from the link. Cyborg plant.