PROBLEM:
While dropping APEX user got below error in oracle 12c, got below error.
SQL> drop user APEX_050000 cascade;
drop user APEX_050000 cascade
*
ERROR at line 1:
ORA-28014: cannot drop administrative users
SOLUTION:
set _oracle_script
to TRUE and execute drop command as below.
SQL> alter session set “_oracle_script“=true;
Session altered
SQL> drop user APEX_050000 cascade;
User dropped.