"Hotplug" refers to any device which can be plugged unplugged without stopping the Computer
these devices are labelled "USB"
Why this is showing an error is a mystery
I have just fitted a USB webcam which I "Plug" and "Unplug" without problems an icon flashes up in the toolbar followed by a brief message on the desktop says that the webcam has been detected.
Only thing I can suggest is if you have any thing which is USB such as a Mouse, Keyboard, ect switch on the computer pull out and replace the connectors to the USB sockets which are small rectangular and the plug has a stylised "Fork" design on it (the square end plug goes to the device)
Turn the sound on you will hear a Xylophone sound
when the USB plug is put in or taken out,
The other thing which can cause this problem is if there is something has shipped "loose" inside the computer tower but you or nobody else has been poking around in there?

or lifted and dropped the computer case? even by a small amount? It does happen,the shock of it just "may"? move a motherboard component slightly for the computer to signal that somethings come undone.
Same goes for a loose or badly routed connection
Bottom line: Think of anything that you have which is USB Labelled plug it in and then unplug it
or switch off with the object connected
It may clear that error note from your toolbar?
