If the data is important stop what you're doing at hand the device to a DR pro.

HDDSC skips ahead when it encounters a read error, when there are too many of those read errors without any good data being read HDDSC stops trying to copy data. There is a high degree of probability either there is head damage or damage to the platter surface although I have also seen this from firmware corruption.

There are tweaks to setting that can be made, you can try skipping that area of the disk or reading in reverse, but if the data has monetary or sentimental value I would suggest not hammering the drive and risk turning the data into dust.

If you post the log file I'll take a look.

The slow fix performs writes to the service area, and if something goes horribly wrong, it can possibly brick the drive. There is more of a chance of something going wrong through USB, SATA is safer. Usually it goes okay either way, but again, SATA is just safer when applying the slow fix.

And when recovering a failing SATA drive, it is always better to connect directly via SATA and not use a USB adapter. The adapter can add extra issues.

After running the slow fix, do not increase the skip threshold. The whole purpose of the fix is to fix the slow responding issue. Increasing the threshold could cause an issue with lack of skipping if there is a bad spot or weak head.

I tried running the WD Slow Fix with HDDSuperTool it wouldn't run as I got this error;

Did you confirm the need to apply the slow fix and are you connected via sata or usb?

AFAIK USB controllers need to support passing on SATA commands for this to work, no? It's why many don't support SMART while some (newer ones) do.

I'm curious How do you know if the USB controller supports passing on SATA commands, I doubt it will say this anywhere open on the box for example ?

Probably never advertised. My rule is don't buy cheap (Chinese) no brand adapters. I have had one that didn't even report bad reads. Spend the money and get one that actually has a brand name. For instance I have had good luck with Sabrent adapters. Startech is another brand that comes to mind. A brand name will usually not want to sell you a totally junk item as it can hurt their reputation.

I know you strongly recommend directly using SATA directly; although, would you recommend this https://www.sabrent.com/product/USB-DSC ... escription
as a very close identical alternative ?

I would not call it a close identical alternative, just because I would not call any USB adapter a close identical alternative to a direct SATA connection. But yes, that should work. I have the 2.0 version of that adapter and it definitely passes ATA commands. I also have the following docking station from them and it also passes ATA commands. It is a bit costly, but to me shows the 3.0 version of their products will pass the ATA commands.
https://www.sabrent.com/product/EC-HD2B ... -function/

HDDSuperClone 2.2.24_20210801
No activation license found.
HDDSuperTool 1.10_20170129
Scripts 1.9_20190413

Q) Quit
A) ATA Passthrough
S) SCSI Passthrough
D) Direct IDE
Choose which mode > a
Finding devices

Q) Quit
R) Refresh drive list
1) /dev/sda (240057409536) PNY CS900 240GB SSD PNY0618223915020ED75
2) /dev/sdb (120034123776) KINGSTON SH103S3120G 50026B724400B7D1
3) /dev/sdc (1000204886016) WDC WD10EZRX-00A8LB0 WD-WMC1U7009051
4) /dev/sdd (750156374016) WDC WD7500AADS-00M2B0 WD-WMAV50568496
5) /dev/sde (0) sense-data 05 20 00
Choose which drive > 4

Main menu
q) Quit
h) Toggle script help
1) Device information
2) Read sectors
3) Write sectors
4) Erase sectors
5) Tools
6) Security
7) VSC
Custom
Enter your choice:
> 7
7

VSC menu
q) Quit
p) Previous menu
h) Toggle script help
1) WD dump mod 42 (older Caviar drives)
2) WD royl (Marvel) dump mod 02
3) WD royl (Marvel) dump mod 32
4) WD royl (Marvel) patch mod 02 (slow fix)
5) WD royl (Marvel) patch mod 32 (slow fix additional)
6) WD royl (Marvel) dump all modules
7) WD royl (Marvel) dump selected module
WD royl (Marvel) read rom
9) WD royl (Marvel) check rom file
10) WD royl (Marvel) write rom (dangerous)
11) WD royl (Marvel) write module (dangerous)
Enter your choice:
> 4
4
Western Digital ROYL patch module 0x02 using vendor specific commands.
This is to resolve a common WD slow issue, where the drive reads slow.
Definition of the "slow responding issue":
- The drive is reading very slow, but all reads are GOOD.
This may not help any if the reads are bad due to a weak or bad head.
WARNING: THIS IS DANGEROUS AND COULD KILL THE DRIVE!!!
USE AT YOUR OWN RISK!!!

WD ROYL Patch Mod02
This modifies data in the service area of the drive!
Use at your own risk!
These commands can take several minutes and appear to be hung.
Please be patient and let it finish on its own.
q) Quit
p) Previous menu
1) Read the module to a file and create the patch.
2) Write the patched data back to the disk.
3) Restore the original dump.
Enter your choice:
> 1
1
Performing identify device command
Model: WDC WD7500AADS-00M2B0
Serial: WD-WMAV50568496
Reading the module
enable vsc
prepare for read
Error performing passthrough IO on input device (No such device).
ata28cmd 0xd6 0x01 0xbe 0x4f 0xc2 0xa0 0xb0
There was an error processing the script 'wd_royl_patch_mod02'. Exiting...
Total program run time = 88 seconds

Performing identify device command
Model: WDC WD7500AADS-00M2B0
Serial: WD-WMAV50568496
Reading the module
enable vsc
prepare for read
Error performing passthrough IO on input device (No such device).
ata28cmd 0xd6 0x01 0xbe 0x4f 0xc2 0xa0 0xb0
There was an error processing the script 'wd_royl_patch_mod02'. Exiting...
Total program run time = 88 seconds