Here is a little more info
dfu-programmer at32uc3b1256 flash --suppress-bootloader-mem c_duck_v2_S001.hex --debug 6
target: at32uc3b1256
chip_id: 0x2ff6
vendor_id: 0x03eb
command: flash
quiet: false
debug: 6
device_type: AVR32
------ command specific below ------
validate: true
hex file: c_duck_v2_S001.hex
Error parsing the line.
Something went wrong with creating the memory image.