While transferring 200k files to my USB HDD, it stopped and when remounting the disk, I got:

Error mounting /dev/sdj1 at /run/media/karlo/WD: Command-line `mount -t “ntfs” -o “uhelper=udisks2,nodev,nosuid,uid=1000,gid=1000,dmask=0077,fmask=0177” “/dev/sdj1” “/run/media/karlo/WD”‘ exited with non-zero exit status 13: $MFTMirr does not match $MFT (record 0).
Failed to mount ‘/dev/sdj1’: 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.

Fix is:

$ sudo ntfsfix /dev/sdj1 
Mounting volume... $MFTMirr does not match $MFT (record 0).
FAILED
Attempting to correct errors... 
Processing $MFT and $MFTMirr...
Reading $MFT... OK
Reading $MFTMirr... OK
Comparing $MFTMirr to $MFT... FAILED
Correcting differences in $MFTMirr record 0...OK
Processing of $MFT and $MFTMirr completed successfully.
Setting required flags on partition... OK
Going to empty the journal ($LogFile)... OK
NTFS volume version is 3.1.
NTFS partition /dev/sdj1 was processed successfully.

ntfsfix is a part of ntfsprogs.