The default Oracle 12c database installation (that a lot of developers will use without going into the advanced setup) is a bit strict. For instance you can’t just create users that don’t comply to the user naming policies. But what about “sys” or “system”? They don’t comply either!
Add the following to your script:
alter session set "_ORACLE_SCRIPT"=true;
Things should work now. Basically you’re acting like you’re an Oracle supplied script now. And we know the rules don’t apply to Oracle, right?