APEX 5.0: There are issues with the configuration of the Static Files in your environment.
Oracle HTTP Server (OHS) / modplsql
2. Add the following values to the APEX DAD definition in dads.conf:
3. Restart the OHS so that these new values will be recognized.
Issue is resolved.
For different HTTP services like ORDS and Embedded PL/SQL Gateway use the note id:Doc ID 2004672.1