The file that you want to print is not listed in the USB Flash Drive
You might be trying to print a file type that the USB printing feature does not support. The product
supports .PDF and .JPEG file types.
You might have too many files in a single folder on the USB flash drive. Reduce the number of files
in the folder by moving them to subfolders.
You might be using a character set for the file name that the product does not support. In this case,
the product replaces the file names with characters from a different character set. Rename the files
using ASCII characters.
Chapter 9 Solve problems