Mac kan ikke læse ekstern harddisk

Jeg har problemer med en ekstern harddisk, som kan ikke læses hverken af en mac eller windows computer. Når jeg tilslutter den på Mac, får jeg nedenstående fejlmeddelelse. Hvad skal jeg gøre ved det ?

Tuxera NTFS could not mount /dev/disk1s1
at /Volumes/TOSHIBA EXT because the following problem occurred:

Aligned I/O enabled.
CBCIO enabled.
WARNING: ReadFully - I/O error while reading from file (5: "Input/output error")
WARNING:  failed at: pread(3, 0x100680000, 524288, 98041856);
WARNING:  bytesRead=0
ntfs_attr_pread_i: ntfs_pread failed: Input/output error
Failed to read $UpCase, unexpected length (-1 != 131072).
__ntfs_volume_release(): Inode 10 still have 1 references.
Failed to mount '/dev/rdisk1s1': Input/output error
NTFS is either inconsistent, or there is a hardware fault, or it's a
SoftRAID/FakeRAID hardware. In the first case run chkdsk /f on Windows
then reboot into Windows twice. The usage of the /f parameter is very
important! If the device is a SoftRAID/FakeRAID then first activate
it and mount a different device under the /dev/mapper/ directory, (e.g.
/dev/mapper/nvidia_eahaabcc1). Please see the 'dmraid' documentation
for more details.