Debugging an APEX application

An essential part of the development process of almost any software project is debugging. A good debug method allows developers to exactly pinpoint problems in the application.
Application Express offers some built-in functionalities to debug applications, pages, and even items. This recipe will explain how to set up debugging on an application and how to interpret the reports that APEX generates.
Getting ready
The only thing we need to start on this recipe is a (working) application. We will use a simple application, based on the EMP table.
Create a new application with a form and report (based on an interactive report) on the EMP table. That is enough to get through this recipe.
How to do it...
First of all, debugging has to be enabled for the application. By default, this option is disabled.
To enable debugging, perform the following steps.
In the Application Builder select the application that we are going to debug.
Locate the button labeled Edit Application Properties...
