Error when using DBCA to create database I am using Oracle Database XE (18c). The install completed without any error however, when I try to create a database using dbca it shows error: java.lang.NullPointerException.

The log is:
https://ghostbin.com/paste/G0SEb
I am still very new to Oracle. How can I solve this?
This is in your log file:
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Global Settings
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- 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 &quot;sales.us.example.com&quot;. The first part of that name becomes the &quot;SID&quot; value, and must not exceed 8 characters in length (e.g. &quot;sales.us&quot;). 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