The file system of your USB drive or external device is FAT32 or FAT16, which has limitations to the file size.Indeed, the possible reasons for this problem are:
You may experience the same situation as above and cannot figure out why the drive that has enough space is unable to handle the large file. Then I received a prompt: 'File is too large for the destination file system.' But I am sure the drive has plenty of free space to store the file. 'I just plugged in a new external hard drive and was ready to copy everything I needed.