Hello,
You must enable debugging to see what makes the error 500. In configuration.php set:
Code:
public $debug = true;
and
Code:
public $error_reporting = 'maximum';
We can't help you with Joomla upgrades as it's a complicated task that must be done by Joomla professionals. Our support doesn't include this. If you want, we can give you our offer for upgrading any website from Joomla 3 to 4.
If you have a website that is upgraded to Joomla 4 improperly (has errors after the upgrade), you should restore your Joomla 3 website from backups. This is usually the only solution before trying to upgrade again.
Regards,
Milos
