WD My Book Not initialized / Unallocated

UPDATE (ISSUES SOLVED):
-Internal disk is wiped clean and a letter has been assigned to it. Everything is working great.
-External disk transfers are done through GetDataBack and as soon as I am done checking if I didn't miss anything, I will be wiping this disk as well. However, I will complete that step after the Holidays since 3TB of data through the Guttman method will take a long long long while.

We can consider my issues as SOLVED! I am glad I had some base knowledge to start with because I would never have succeeded. To each problem, there is a solution! Data just does not disappear into thin air.

Thank you Jumanji for advising GetDataBack. I personally, through all the software I tried, recommend GetDataBack and Active Data Studio. These are the only two that worked between

-R-Studio
-Acronis True Image WD Edition
-Stellar Phoenix
-MiniTool Partition Wizard Free
-TestDisk

Will be making a final update after the Holidays.

*UPDATE*:

Foremost, Happy New Year to everyone.

-Internal disk has been found to contain no bad sectors and is in perfect working order. Now serves as a secondary hard drive for storage.
-My SSD is blazing fast and I wonder why I waited a year before installing it.
-External disk is online and in working order. However, it has one bad block containing bad sectors from 0 to 19839 which relates to about 60 MB. I could always make a partition of that space and never use it, which would fix the issue. I will restart my system once I am done rewriting the entire disks with zeros and attempt a repair disk at the DOS level.

Any other ideas?

CHKDSK results

*UPDATE*

-Here are the results of the chkdsk scan and repair. It found as expected, 1 block of bad sectors and moved it to the bad clusters file.

Any input on what to do next? The hard drive is functional and formatted.

Hi, i'm happend the same problem, but i cant return the disk to MBR, i try firt with Active data studio & GetData Back but i cant fix it, i think i need to repair permission or something, i try to follow your steps but nothig, please if you can help, please!!

Hi Jumanji, i have the same problem well i think, i hope you can help me, my disk fails and i initialize the disk to GPT, and now i can see it but the disk its unallocated, and when i run getdataback the program tellme the error 21 in HD129 too many many times and in the final dont rescue anything, i think i need first initialized the disk to MBR but i dont know how...please if you can help me please!!