Dolphin, that is most likely a USB connection error.
Clean the ends of the cables, switch USB ports, (while the machines are OFF) if that doesn't work try another cable.
When your dealing with printers, assume hardware connection issues first.
I turn off my printer(s) but use the Brother everyday, the epson everyother or so. Leaving them off for a longer time will dry out the ink/heads, but even that will not give you the error you have received.
A software error is different than the one you have posted.
You have a USB connection error, I have gotten them myself.
Sandbox. I just switched USB ports as you suggested and the annoying message is gone. I tried it several times and it did not show up again.