Below procedure was tested using Windows Server 2012 R2 Datacenter and SSO 8.4.0
When upgrading SSO you must run adaminstall.cmd script with same user as originally installed the database. The users that have sufficient access rights for running adaminstall.cmd are listed in LDAP CN=Configuration,CN={993612A3-D948-4D4A-8690-125E5AFF0241},CN=Roles,CN=Administrators.
If those usernames are not known or not accessible you need to change the ownership to a new user. Running adaminstall.cmd with user that is not ADLDS administrator would result in errors like:
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