Security Update 2020-001

I was finally able to successfully install the Security Update 2020-001 for High Sierra on my Macbook Pro Retina 13" 2015.

Please excuse me for my brevity as English is not my native language.

Below is the chronology:

1. I experienced the problem as described by PossumGouge, and applied the fix authored by nonhillside.
2. I checked my Activity Monitor and noticed that the mds_stores and mdsworker (Spotlight indexing process) had been running for 12 hours after the fix applied, using 80% CPU and resulting of 8GB of bytes written - which is not normal. The Spotlight's search was also no longer working.
3. After forcing Spotlight to reindex, still no files or directories could be found.
4. I opened Disk Utility and ran First Aid check on my volume. The check was not completed and a bad snapshot metadata tree was reported saying:

** Checking the snapshots.
error: fext_val : object (oid 0x14): Bad phys_block_num+len for physical file extent record, phys_block_num 2508084 len 8192
Snapshot is invalid.
** The volume /dev/disk1s1 could not be verified completely.

5. To repair this, I restarted my system normally and in a terminal prompt, I listed the snapshots created :

$ tmutil listlocalsnapshots /
com.apple.TimeMachine.2018-03-20-112749 (dataless)
com.apple.TimeMachine.2018-03-21-174756
com.apple.TimeMachine.2018-03-22-074442

6. I then deleted the dataless snapshot:

$ tmutil deletelocalsnapshots 2018-03-20-112749
Deleted local snapshot '2018-03-20-112749'

7. I ran First Aid check again using Disk Utility and the disk verification was able to be completed with no issues found.

8. I checked spotlight again and the mds_stores process (Spotlight indexing) was still running wildly.

9. I opened the Console app, and found many error messages related to LaunchServices, such as this:

errore  16:19:03.743247 +0100   mds LaunchServices: Database mapping failed with result -10813, retries = 7

10. I then followed the advice from FreeNickname at Apple StackExchange under a thread titled "Spotlight re-indexing takes too long or doesn't work" to resets the Launch Services Database, resets the Dock, and triggers Spotlight reindexing, by running:

sudo /System/Library/Frameworks/CoreServices.framework/Frameworks/LaunchServices.framework/Support/lsregister -kill -seed -lint -r -f -v -dump -domain local -domain system -domain user -domain network

killall Dock

sudo mdutil -E / 

10. I left my Mac for about 1 hour, and then noticed that the Spotlight was working normally, files and directories can be found and mds_process was no longer the highest CPU user, and the bytes written was far lower.

11. Finally - after Disk First Aid was completed and Spotlight re-indexing is normal (files and directories) - I went to App store to re-download the High Sierra Security Update 2020-001 again.

12. The installation was successful, however, after several blank screen and auto-restarts that caused several nerve breaking.

I am not anywhere near an Apple developer, however, the update may require that there is no dataless Time Machine snapshot, and reset/fix of Launch Service Database.

As per the time of writing, my Mac is working normally.