Joomla 4/5 User Manual
The System Setup panel contains a link to the Global Configuration form. You may also access the form from the Home Dashboard. The form contains options that apply to your site as a whole. On installation the options are populated by mostly suitable default values. If an option turns out to be unsuitable for your site you can change it permanently. Or you may need to make temporary changes for trouble-shooting purposes.
The form has a Toggle Inline Help button in the Toolbar. Try it - information about some of the fields will appear or disappear with each click of the button. That often avoids the need to look up other information in Help screens or Tutorials like this one.
The configuration.php file¶
In the root of your Joomla installation is a file named configuration.php. It is created during installation and is never overwritten by an update because a file with that name is not present in any installation or update package. The file contains the options you set in the Global Configuration form. It is assigned read only permissions in most hosting environments so normally you should not edit it with a text editor. When you make a change and save the Global Configuration form Joomla changes the permissions, writes out the new options and then changes the permissions back to read only. If something goes badly wrong you may be advised to edit this file to make some changes manually. In that case you need to change the file permissions to read-write yourself.
Site / Cookie¶
Under the Site tab there is a Cookie panel. Both fields are normally empty. However, if you run multiple Joomla installations from one parent folder you may wish to set the Cookie Path the folder name of the installation to avoid clashes, sometimes in third party extensions.
If you enter anything in the Cookie Domain field you will find that after logout you will be unable to login again. This is one instance where you will have to edit configuration.php with a text editor, find the line that says public $cookie_domain = 'garbage'; and remove whatever is present between quotation marks, garbage in this example.
If your site displays an error message you will normally have little information on what has gone wrong. There are two things to do in the first instance:
- In the System / Debug panel set Debug System to Yes.
- In the Server / Server panel set Error Reporting to Maximum.
Save and go back to the page that was displaying the error. This time you will see a Stack Trace, a list of points in the code where the error was triggered. With that information you, or someone in the Joomla Forums, may be able to figure out what went wrong. Take a screen shot of the stack trace for your Forum question.
Setting Debug to Yes has several effects:
- At the bottom left of the screen there is a button to open a panel of information about your site. This is a potential security risk so only stay in Debug mode for long enough to obtain a stack trace.
In the System / Session panel there is an option to select a Session Handler. Database is the deafult because it is the only one guaranteed to work. If it did not work then Joomla itself would not even install. If you change the Session Handler and your site crashes you need to edit configuration.php and set public $session_handler = 'database';.
In the Server / Mail panel the default settings that have Mailer set to PHP Mail are likely to work on a hosting service but not on localhost on your own computer. For localhost change the Mail to SMTP and set the SMTP Host to the one you use for outgoing mail in your mail client. You need to use the same credentials as your mail client uses. Select the Send Test Mail button to check if it is working. Joomla may return a green success message but the mail my never get through.
It is sometime helpful to use logging to help with debugging but it should not be used on a working site. In the Logging panel set Log Almost Everything to Yes and in the Custom Logging panel remove the All category and select the Error category. Load the page that is giving trouble and then use a text editor to open administrator/logs/error.php (just look for files in the logs folder and select the most obvious).
The error log may be similar to the stack trace mentioned previously. It may help you to identify the source of a problem.
Set Log Almost Everything to No when done!