oracle – Error when using DBCA to create database

This is in your log file:

------------------------------------------------------------------------------
Global Settings
------------------------------------------------------------------------------

- Global database name : course_management
- Configuration type : Oracle Single Instance database
- SID : coursemanage

Global Database Name is meant to be a fully qualified name, like “sales.us.example.com”. The first part of that name becomes the “SID” value, and must not exceed 8 characters in length (e.g. “sales.us”). In other words, pick a much shorter name.

See here: https://docs.oracle.com/en/database/oracle/oracle-database/18/ssdbi/about-assigning-global-database-names-during-installation.html#GUID-1AC9E18F-0AE4-4263-B3CC-A83B859A178F