Brother MFC 9560CDW - Manual (Page 119)

Troubleshooting
103
B
Too Many Files
There are too many files stored
on the USB Flash memory drive. Reduce the number of files stored on the
USB Flash memory drive.
Unusable Device
An incompatible or defective
device has been connected to the
USB direct interface. Remove the USB Flash memory drive from
the USB direct interface.
WT Box End Soon
The waste toner box is near the
end of its life. Buy a new waste toner box before you get a
Replace WT Box
message.
Error Message Cause Action