gistfile1.txt

Unable to access “399 GB Volume”
Error mounting /dev/sda2 at /media/ubuntu/5b3539e9-5a47-3bda-af62-68d74a53b840: Command-line `mount -t "hfsplus" -o "uhelper=udisks2,nodev,nosuid" "/dev/sda2" "/media/ubuntu/5b3539e9-5a47-3bda-af62-68d74a53b840"' exited with non-zero exit status 32: mount: wrong fs type, bad option, bad superblock on /dev/sda2,
       missing codepage or helper program, or other error
       In some cases useful info is found in syslog - try
       dmesg | tail  or so


The end of `dmesg | tail`
[ 4060.003754] hfsplus: invalid secondary volume header
[ 4060.003762] hfsplus: unable to find HFS+ superblock