To turn on Joomla!'s Debug mode:

• Login to the Joomla administration e.g. http:/YOURSITE/administrator/
• At the top under the Site menu click Global Configuration.
• Click the System tab.
• Under the Debug Settings section change Debug System to Yes.
• Click the Save button.

Debug mode will output a list of all queries that were executed in order to generate the page. This will also turn on a stack trace output for error and warning pages. Hubzero components will also have PHP error reporting turned on, allowing one to see any PHP errors that may be present.

Note: Turning on debugging mode for production (live) sites is strongly discouraged and it is recommended to be avoided if at all possible.

One encounters the following error:

Illegal variable _files or _env or _get or _post or _cookie or _server or _session or globals passed to script.

This error is generated when the key of a key-value pair is numeric in one of the following variables: _files or _env or _get or _post or _cookie or _server or _session or globals. An example of this would be $_POST[5] = 'value'. This is most often generated by having form elements with numeric values as names. For example:

<input type="text" name="5" />

As the error indicates, this is not allowed. Element names must include at least one non-numeric character. Examples:

<input type="text" name="n5" />

<input type="text" name="n_5" />