Potential solution to ORA-1033 during configuration of standby database in data guard broker

In my environment, the following message was displayed in dgmgrl when trying to configure a data guard environment:

DGMGRL> add database 'hdal_stb' as  connect identifier is 'hdal_stb';
Error: ORA-1033: ORACLE initialization or shutdown in progress

Failed.

I had prior to this attempt duplicated the target database to the auxiliary using "duplicate target databas for standby from active database" - and the output looked fine.

Turns out that you cannot set the parameter redo_transport_user to any other value than SYS when cloning for standby.
In my environment, we use a dedicated user for this purpuse, as we avoid using the SYS user as much as possible.

I adjusted the parameter to read SYS on both the primary and standby instance, and reran the duplication.

Afterwards, the database could be added:

DGMGRL> add database 'hdal_stb' as  connect identifier is 'hdal_stb';
Database "hdal_stb" added