I am using Android, Windows and iOS dashboards.
I have tried this on Pi B, B+, 2, 3 and Zero
I am using Raspbian 8.0 (Jessie)
I have several data logging and control systems using 1-wire ds18b20 sensors. Once a sensor has been connected, it cannot be removed from the dashboard even when it has been physically disconnected. My dashboards now each have several unwanted widgets showing disconnected sensors. The Remove Sensor button is grayed out.