KeyError

[dwarning]

I am using latest image Version 0.0.6-git-7050317 under Ubuntu 20.04.
The device is a VC830 dmm connected by USB hid cable. The manual connection and measurement works very well.
`
import smuview
import time

dmm_device = Session.connect_device("voltcraft-vc830:conn=1a86.e008")[0]
dmm_conf = dmm_device.configurables()[""]

dmm_conf.set_config(smuview.ConfigKey.MeasuredQuantity, smuview.Quantity.Voltage)
`
I got following error:

`KeyError: ('',)

At:
/smuview/smuscript/battery_characteristic.py(8):
`
My python is Version 3.8.