NamelessMC

When i try to send an Test mail http error 500

and when someone try to register and press on submit it says http error 500

Hello ?

Can you please enable debugging (StaffCP -> Configuration -> Maintenance) and an error message should appear on screen.

One potential cause is that you are using PHP 8 with the "PHPMailer" option enabled - currently this only works on versions up to PHP 7.4

You know how to downgrade ?

Unfortunately not - there might be some guides online to downgrade PHP 8 to 7.4

I cant find how to downgrad but thats the error

Fatal error: __autoload() is no longer supported, use spl_autoload_register() instead in /var/www/html/core/includes/phpmailer/PHPMailerAutoload.php on line 45