If after migration from our old systems (h-sphere) you find that your website is showing an internal server error or 500 error one of the first places to look is your .htaccess file. This file is usually present in your domains root directory but may also be in other directories depending on your setup.
The two most common causes of these errors that we see are php_flag, and php_value being defined in .htaccess. On our old servers this was possible, in Plesk it is handled differently, such as by your PHP settings page as shown here:
Any php_flag or php_value lines in .htaccess you can either remove or disable by commenting them out by adding a # at the start of the line. If you need a value or flag that is not available from your PHP settings please contact our support team