Blank page, or Internal Server Error

Under some circumstances, suddenly the page content disappears and becomes blank. No content, no errors, nothing. The developers call this the White Screen of Death or WSOD.

There are several reasons, and several different solutions, therefore it's important obtaining detailed information about the error occurred.
When error displaying is turned off and a fatal error occurs, neither the content nor an error message will be displayed, therefore you end up with a completely blank page.
For security reasons, on production sites, it is common to have error displaying turned off, but error messages are one of your best tools for troubleshooting.

You need to either

• Enable the PHP error displaying in order to have error messages displayed on the page itself when an error occurs, or
• Consult the Log Files of your web server looking for the error message.

Note
Depending of the nature of the problem, it can appear as Error 500: Internal Server Error.
In that case, Enabling the PHP error displaying won't help you. Consult the Log Files of your web server instead.

Enable the PHP error displaying

The easiest way to show php errors is to set the "Error Reporting" option to "Maximum" under "Joomla Global Configuration" > "Server" > "Server Settings".

In case that the "Error reporting" option doesn't work, add the following instructions at the end of a file called .htaccess which should be present in your joomla root directory. In case it is not present, or it is called htaccess.txt, simply create a new file and call it .htaccess (don't forget the dot at the beginning of the name).
The configuration is active as soon as the file .htaccess is saved. Reproduce the server error to see on the page the details about the error.


Consult the Log Files of your web server

Fatal php errors are logged to the system log of your web server. After a White Screen of Death or an Internal Server Error occurs, open the log file and read the details of the error occurred.
The place where the log file is, and the way it can be accessed, vary depending on your Internet Service Provider, but it is good to know what and where your log file is.
Often it is accessible outside your web document root using your ftp client, or it is available through your web space administration panel.

Do not confuse the system error log with your Joomla error log, which is located under your Joomla /logs directory.

Some providers don't allow access to your error log. In this case, try enabling the error displaying.

Warning!

Many ISP's hosted servers run PHP in suPHP mode.
Any 'php_flag' directive in .htaccess on these servers will itself cause a '500 Internal server error'.

Any 'php_flag' directive in .htaccess on these servers will itself cause a '500 Internal server error'.

Well, our attempt to detect the server error would cause another server error. That's the magic of php :)
It seems that the "Error Reporting" Joomla option is the best way.