[PLUG] Odd USB Volume

[Dick Steffens]

Machine is running Ubuntu 18.04 MATE but with Xfce for the window manager.

Once in awhile an icon appears on my desktop labeled 4.1 KB Volume. The 
image has the USB symbol, the trident with a circle, and arrow, and a 
square. There is no USB storage device currently connected to the 
machine, although I used my SD card reader one day last week. My 
recollection is that it goes away when I reboot.

Right clicking on it gives me four options:

Open,
Mount Volume,
Properties (grayed out),
Applications

Applications is expandable and has the same list as the Applications 
list in the top line menu.

Clicking on Mount Volume give me a small window labeled Mount Failed and 
containing the text

Failed to mount "Volume"
The given volume was not found

It doesn't show up in a Thunar window (although I think it did once), 
and it doesn't show up in a terminal window using ls -l. Hovering over 
it produces a floating image with the text, "Removable Volume Not 
mounted  yet".

Does anyone have any idea why I get this icon?

-- 
Regards,

Dick Steffens