Trying to remove what I assume is a ghost. When the Zwave Details page has an entry like below. What exactly does PENDING indicate? And why does Remove not remove the device? This device has no route, no device name, but it does show 2 neighbors.
I'm on a C7 with platform 126.96.36.199 and I have updated Zwave.
The reason it won't remove is because the device that created it is still online and pingable. You need to find that device (usually the one right after it) and disconnect power to it. Once you do that, shut down the hub and unplug power to it (at the wall not the hub) for 5 mins and power it back up. Attempt to remove again. If it still fails you will need a z-wave stick paired as a secondary controller and the silabs software to remove it. Ghosts like this are detrimental to your mesh.
often means the ZRadio has a "packet jammed sideways". Since the radios are always powered the only way to reset them is to do a Shutdown from the Settings menu then unplug the hub from the wall, not the micros usb end for 30 seconds or more, as @rlithgow1 suggests.
Right after it comes back, try that Remove again...
@rlithgow1 Just wanted to say thanks for posting this. I had a ghost I couldn't get rid of through the Hubitat UI and needed to use my stick. Instructions were very helpful for getting that accomplished.