White page in the Joomla frontend and backend - troubleshooting

You can see that you can’t see anything! :-)
A blank white page in the Joomla frontend or backend is a common problem that initially leaves many Joomla users puzzled and wondering what happened.
The problem: PHP execution stops because of an error.
Most Joomla installations in live operation respond with a completely blank white page.
The first step toward troubleshooting is to make the error visible.

This should make it clear where exactly the issue occurs.

Bring the white page to life - enable error_reporting and debug mode

If the white page appears only in the Joomla frontend, you can simply set 'Error Reporting' to 'maximum' in the administrator area under Global Configuration. This setting can be found in the Server tab. Enabling debug mode (System tab) can also help.

Administrator page is not displayed

If the backend is also down and no error is shown, the direct approach is to edit the configuration.php.
Because configuration.php is usually write-protected (CHMOD 444), you first need to grant write permissions to the file.
In FileZilla: right-click - File permissions -> 644

The value for error_reporting is now changed in the corresponding line from 'none', 'default' or '0' to 'maximum'. To debug the system, set the configuration variable to 1.

public $error_reporting = 'maximum';
public $debug = '1';

If no error message is still displayed, this is probably because error display has been disabled in the PHP configuration. Depending on the web host, the PHP configuration can be adjusted accordingly in the customer area. Alternatively, a php.ini placed in the main directory with the following content may work.

display_errors = on

If in doubt, information about error_reporting can usually also be found in any well-organized FAQ/help section of your web hosting provider.

Here is another relevant video on the topic from joomlainfo.ch:

Lade YouTube Video

Typical causes of blank Joomla pages

1. Failed updates
2. Incorrect / PHP version set too high (possibly raised automatically by the host)
3. memory_limit too low (often caused by visitor counter or gallery extensions when compressing excessively large photos)
4. Incomplete / only partially uninstalled extension packages

White page after Joomla update

Disable incompatible extensions

Often, after a Joomla update errors occur with the extensions in use, which may not be compatible with the new version. Depending on when the incompatibility interferes during the update process, the update may even fail completely. Therefore, especially with major version jumps (2.5 to 3), it is advisable to before the update disable all third-party extensions. A practical approach is to go to Extensions -> Manage and sort by ID in descending order. Then display 30-100 entries per page, select all entries with ID > 10000 (= 3rd party), and disable them.

If the site is already white due to an incompatibility and shows an error message, the triggering extension can be disabled directly in the database via phpMyAdmin.
-> In the #__extensions table, change the value for 'enabled' from 1 to 0.

After that, the problematic extension can be updated in the backend and re-enabled.

Tip #1 for troubleshooting

Google the error message!
You usually get the best results with suitable solutions by putting the last part of the displayed error message (/path/filename + line) or key parts of the message in quotation marks when searching on Google.

Examples:

'/plugins/system/logout/logout.php on line 48'
'JHtmlBehavior::mootools not found.'
'/libraries/cms/application/site.php on line 669'
'undefined method JAdminCssMenu::addChild()'
'/modules/mod_sppagebuilder_admin_menu/tmpl/default_enabled.php on line 16'

Joomla is widely used, and there is a good chance that someone else has already had exactly the same problem before.

• Prev