Ubuntu_Image_Build_Fail

PC:~$ /snap/bin/ubuntu-image -d --channel edge --image-size 4G --extra-snaps eragon_4.4.23_arm64.snap --extra-snaps eragon-kernel_4.4.23_arm64.snap -o uc16-eragon.img eragon.model
DEBUG:ubuntu-image:-> [ 0] make_temporary_directories
DEBUG:ubuntu-image:-> [ 1] prepare_image
Fetching core
Copying "eragon-kernel_4.4.23_arm64.snap" (eragon-kernel)
Copying "eragon_4.4.23_arm64.snap" (eragon)
eragon already prepared, skipping
eragon-kernel already prepared, skipping
error: bad CRC: 1869570677 != 1876078605
ERROR:ubuntu-image:COMMAND FAILED: snap prepare-image --channel=edge --extra-snaps=eragon_4.4.23_arm64.snap --extra-snaps=eragon-kernel_4.4.23_arm64.snap eragon.model /tmp/tmpx6bni4hw/unpack
ERROR:ubuntu-image:Full debug traceback follows
Traceback (most recent call last):
  File "/snap/ubuntu-image/44/lib/python3.5/site-packages/ubuntu_image/builder.py", line 118, in prepare_image
    self.args.channel, self.args.extra_snaps)
  File "/snap/ubuntu-image/44/lib/python3.5/site-packages/ubuntu_image/helpers.py", line 116, in snap
    run(cmd, stdout=None, stderr=None, env=os.environ)
  File "/snap/ubuntu-image/44/lib/python3.5/site-packages/ubuntu_image/helpers.py", line 97, in run
    proc.check_returncode()
  File "/snap/ubuntu-image/44/usr/lib/python3.5/subprocess.py", line 349, in check_returncode
    self.stderr)
subprocess.CalledProcessError: Command '['snap', 'prepare-image', '--channel=edge', '--extra-snaps=eragon_4.4.23_arm64.snap', '--extra-snaps=eragon-kernel_4.4.23_arm64.snap', 'eragon.model', '/tmp/tmpx6bni4hw/unpack']' returned non-zero exit status 1