Hello to all
I have a serious problem with my external HDD. It has been removed unproperly, so now, when I want ot mount it, I have the following message:

Error mounting: mount exited with exit code 13: ntfs_mst_post_read_fixup_warn: magic: 0x43425355 size: 4096 usa_ofs: 589 usa_count: 65535: Invalid argument
Actual VCN (0x800006009000000) of index buffer is different from expected VCN (0x0).
Failed to mount '/dev/sdb1': 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.

the disk is partition into two. I have very important documents in the both partitions.
thank you for your help

Did you do as stated ?. What happened ?.

We can't help if you won't help yourself. NTFS is proprietary - if you have a filesystem in error, you'll (first) have to us the M$oft software.