This happens in the web dashboard.
I call ‘dead’ sensors the sensors that are proposed when data coming from new channels are acquired for the first time.
They appear in a green box. I click on the ‘+’ button and the sensor is added to the sensor list (left panel).
The problem is that this sensor/widget is than not usable anymore. It seems dead.
And this sensor/widget seems producing also ‘Server error’ on the Android App.
It can’t be removed or more in general the properties can be exploited.