Your post is a little light on details. The manual writes:
"Before you connect a USB device
Compatibility: USB storage
• If the file name of a folder on a USB device exceeds 10 characters, it
is not displayed on the VFD.
• This product may not be compatible with certain types of USB
storage media.
• The file systems FAT16 and FAT32 are supported.
-- The NTFS file system is not supported."

That's a lot more in the manual and for most folk, they will not want to follow those rules.