Support

Akeeba Backup, like all Joomla! components, uses Joomla!'s com_config to handle the display, edit and save of all component parameters. It's the same as clicking the Options toolbar button in any other component. Therefore the 500 Internal Server Error is caused by something inside Joomla!'s core code. I have not written that code and I cannot provide support for it, sorry :(

For what is worth, I have seen that issue only once. It was a failed upgrade from Joomla! 1.7 to Joomla! 2.5. Here's how to test if that's the case. Go to Manage Content and click on Options on the toolbar. Then click on Save and Close. If you get a 500 Internal Server Error you most likely have a failed 1.7 to 2.5 upgrade or another Joomla! issue.

I do have an idea, but it's a longshot. Is it possible that the live server has Apache's mod_security2 (not a Joomla! module, it's a security module for Apache the web server) installed whereas the dev sites do not? I will tell you what I'm thinking. The Download ID is a long hex string. The default mod_security2 rules commonly used may regard this as a potential threat and block the request. Let's do an experiment. Try clearing the Download ID field and save the Component Parameters again. Does Joomla! save them without an error?

Can you try blanking all fields, including any secret key you may have entered?

OK, a white page or a page with a 500 Internal Server Error is, in fact a PHP fatal error in disguise.

First, check your server's error logs (not the access logs) immediately after visiting the page which throws the error. There should be an exact description of the PHP fatal error which occurred. Sometimes you can find the error messages in files called error_log or error.log inside the site's root and/or administrator directories. If unsure about the error log location, please consult your host. Most likely the error logs are available in your site's cPanel, Plesk control panel or similar hosting account management facility.

If your host does not give you access to the error logs and you have access to the Joomla! administrator area, please log in to your site's back-end, go to Global Configuration, click on the Server tab and set the Error Reporting to Maximum (Joomla! 1.5) or Development (Joomla! 2.x and later). Try visiting the problem page again.

If you still get a blank page, edit your configuration.php file and put the following code right after the final closing curly brace ( this is what a curly brace looks like --> } ) but before the closing PHP tag (it looks like ?> that is a question mark and a greater-than sign):

ini_set( 'display_errors', true );
error_reporting( E_ALL ); 

Try visiting the problem page again.

If you still get a white page, please remote the two lines from your configuration.php file. Edit the .htaccess file in your site's root. If you don't have a file named .htaccess create a new one. Beware that htaccess.txt is a DIFFERENT FILE and will NOT work! Add the following to the end of the file:

php_flag display_errors On
php_value error_reporting 32767

and retry loading the problem page.

If you still get a white page, remove the two lines from your .htaccess file. Now, create a file called php.ini with the following content:

display_errors=on
error_reporting=E_ALL

and upload it into your site's root and your site's administrator directory. Retry loading the problem page.

If you still get a white page, delete the php.ini files your created and choose a different host. If your host doesn't allow you to debug any PHP-related issues there is no point paying them.

Please note that if you can not understand what the PHP error message means, just copy and paste it here verbatim so that we can take a look and point you to the right direction.

That's not really helpful. Not PHP errors are being recorded. Try the next steps for enabling more verbose error reporting.

OK! Once you get access to the PHP error, please paste it here.