Cannot Start ADFS Service after changing the Database Connection string to support SQL Always On

Description:
You have configured the first ADFS 2016 Server with SQL as the Database. Later on the day, the SQL Admin has also set the ADFS Database to have Always On capability.

You've follow the syntax from https://docs.microsoft.com/en-us/windows-server/identity/ad-fs/design/federation-server-farm-using-sql-server to change the SQL Connection string on the first ADFS server to support SQL Always On feature.

However when you try to restart the ADFS service, it is always failed.

Example Script:

PS:\>$temp= Get-WmiObject -namespace root/ADFS -class SecurityTokenService
PS:\>$temp.ConfigurationdatabaseConnectionstring="data source=<SQLCluster\SQLInstance>;initial catalog=adfsconfiguration;integrated security=true"
PS:\>$temp.put()

Resolution:

You need to modify the above example script. Make sure the "data source" are correct, and also the "initial catalog" value are the same as the actual database name in SQL. For example you may need to write "adfsconfgurationv3" instead of just "adfsconfiguration" on the above script.