There may be times that your Joomla installation has problems and you want to find out the source of these errors.

Joomla 3 Debugging Tools

If the Debugging tools in Joomla are enabled, Joomla will place code on the screen that will let you know where the errors are occurring. If the site is live, you need to have these tools turned off as they can confuse the visitor and present security risks.

To enable these Debugging tools:

Administration > Site > Global Configuration > System > Debug Settings > Debug System > Yes (Default = No)
Administration > Site > Global Configuration > System > Debug Settings > Debug Language > Yes (Default = No)
Administration > Site > Global Configuration > Server > Server Settings > Error Reporting > Maximum (Default = System Default)