On my play environment I usually use Oracle APEX with the Embedded PL/SQL Gateway, just because it's so easy.
When a new version of APEX is released, just like everybody else, I upgrade my play environment.
After the apexins.sql script is run, I always want to start playing with it immediately. Usually it is at this point where I just see a blank page... scratching my head wondering why it is not running,... having to go back to the documentation to realise I forgot the last step - configure the EPG...
Now with APEX5 an alert is shown when you forget the last step:
Another one of those little enhancements that makes APEX5 simply awesome.