If one of these messages does appear, then try a different USB drive and verify the drive is 2.0 certified. To verify the 2.0 certification and the file formats of a particular USB storage device, plug the USB device into a PC. Go to the Windows Explorer and right click on the Removable Disk (USB Drive) and select Properties. See image below
The General tab in the Properties window will identify the certification and the file format. See image below