'Element not Found' when using EFS on Windows 2008

Recently I had an encounter with a couple of error while migrating from 2k8R2 to 2019

Keyset does not exist 0x80090016 (-2146893802 NTE_BAD_KEYSET)
Client has requested stop service 0xc8000531 (ESE: -1329 JET_errClientRequestToStopJetService)
Keyset does not exist
Element not found

Task-I (Existing Server 2008 R2- Prior to migrating to new OS - 2016 / 2019

1) Backup the Root CA and registry configuration
2) Change the Key CSP to KSP
3) Update the algorithm from SHA1 to SHA2
4) Validate the behavior of Root CA and issuance, template issuance

Task-II

1) Deploy temporary Windows Server 2012 R2 in Azure, Patching and Antivirus should be in compliance
2) Backup the Root CA database and Registry configuration
3) Migrate the Root CA from 2008 R2 to 2012 R2
4) Restore the DB and registry changes to the temporary 2012 R2 server name and update ADSI (PKI enrollment), CDP, AIA container accordingly
5) Validate the Root CA health, CRL status, CA issuance, new template request
6) Once the Root CA is healthy on 2012 R2, then back up the Root CA database, registry configuration,
7) Migrate the Root CA from temporary 2012 R2 to 2016/2019 server
😎 Restore the DB and registry changes to the temporary 2012 R2 server name and update ADSI (PKI enrollment), CDP, AIA container accordingly
9) Validate the Root CA health, CRL status, CA issuance, new template request
10) Once the Root CA is healthy in 2019, then configure the CA backup scheduler, other baselines, etc.
11) Decommission the old Root CA W2k8R2 and temporary 2012 R2 server

Ref : ADCS migration :-
https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-r2-and-2012/dn486805%28v%3dws.11%29
https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2008-R2-and-2008/cc742388(v=ws.10)?redirectedfrom=MSDN