Try to read the error message!
`Invalid config for [knx]:
value must be one of
['battery', 'battery_charging', 'cold', 'connectivity', 'door', 'garage_door', 'gas', 'heat', 'light', 'lock', 'moisture', 'motion', 'moving', 'occupancy', 'opening', 'plug', 'power', 'presence', 'problem', 'safety', 'smoke', 'sound', 'vibration', 'window']
for dictionary value
@ data['knx']['binary_sensor'][7]['device_class']. Got 'None'.
[/quote]
The error is at
data['knx']['binary_sensor'][7]['device_class']
|-> so its in `knx` config
|-> in a binary_sensor entity
|-> the 8th binary_sensor entity to be specific (it's 0-indexed 🤷)
|-> at the 'device_class' key
Got 'None'.
|-> it has to be one of the listed (or omitted completely because it's optional).