Exception: System.Security.Cryptography.CryptographicException: Bad Data. (4262075)

When installing Hotfix_SOL213268-5.6.3 the following error was reported in the event log

Exception: System.Security.Cryptography.CryptographicException: Bad Data.

And in the verbose logs the following error was reported.

System.NullReferenceException: Object reference not set to an instance of an object.

There was an orphaned instance ID under the Realm ID.

1. Log into the PMAdmin site navigate to General Settings | Realm instances

• Take note of the Realm ID & the Instance ID’s

2. On the Active Directory server navigate to Active Directory Users and Computers (ADUC) | Users | PMReplication

• Search for the Realm ID that corresponds to the one found in the previous step
• Verify that the Instance ID’s which are child containers of the Realm ID correspond to the instance ID’s found in step 1

3. If there are any extra instance ID’s listed then these should be deleted as they no longer exist
4. Restart the Password Manager service on each instance and confirm if the issue is resolved