ORA-28014: cannot drop administrative users on Oracle 18.3

Symptom:

  We would like to drop ORDS schemas and reinstall ORDS in 18.3 DB

SQL>  drop user ORDS_PUBLIC_USER cascade;
 drop user ORDS_PUBLIC_USER cascade
*
ERROR at line 1:
ORA-28014: cannot drop administrative users

Solution:

SQL> alter session set "_oracle_script"=true;

SQL>  drop user ORDS_PUBLIC_USER cascade;

User dropped.

SQL>  drop user ORDS_METADATA  cascade;

User dropped.