Use Debug mode to track down unexpected application behavior.

• Enabling and Disabling Debug Mode for an Application
  Configure whether end users can run the application in debug mode by editing the Debugging attribute in the Application Definition.
• Available Debug Levels
  Learn about debug levels available in Oracle APEX.
• Controlling Debug Mode for a Page at Runtime
  Enable and disable Debug mode for the current page and session by clicking the Debug on the Runtime Developer toolbar.
• Configuring Debug Mode Using the Session Detail Report
  View the Session Detail report to review session information and configure Debug Level and Trace Mode for an active session.
• Configuring the Debug Level Programatically
  Use the SET_DEBUG procedure to set the debug level for all future requests in a session.
• Using URL Parameters to Control Debug Mode
  Learn about using URL parameters to control Debug mode.
• Controlling the Debug Level for an Instance
  Change the default instance-wide Debug Level using the APEX_INSTANCE_ADMIN API
• Viewing Debug Messages
  Learn about viewing debug messages.
• Using APEX_DEBUG When Developing Your Application
  Learn about APIs in the APEX_DEBUG package.