A server with a robot was decommissioned and yet the robot still shows up in the Console.
Release: 20.3 or later
Typically if the robot is deleted from within the Console it will no longer show up but it is possible for it to fail in updating the robot.sds file resulting in the robot still showing up.
logs show the UIM is not receiving a response from the device, which means possibly the device is not properly removed.
Feb 24 12:12:13:015  2 hub: internal alarm - Robot device25 is inactive, 5, device25
Feb 24 12:12:13:015  1 hub: heartfailure - device25 is dead
In most cases the robots can be removed via IM > go to the hub that has the robots > hub probe configure GUI > Robots tab > right click on the robot > Remove.
If that fails to work:
stop the Nimsoft Robot Watcher server
move $\Nimsoft\hub\robot.sds to a backup folder
wait at least a full five minutes
start the Nimsoft Robot Watcher server
Sometimes the hub probe will not update robot.sds if the robots reconnect too quickly.
The robots.sds will be automatically recreated without any robots and as they connect back to the hub they get added.
The right click Remove on the robot itself sends a command to the robot, so if the robot is not there it can't remove itself.
The Remove via hub configure GUI uses a hub callback to remove it from the robot.sds and so will usually work.
Also see the following if many robots do not come back after removing the .sds file: