Fatal error: Uncaught Error: Call to undefined function register_activation_hook() in /home/revoluti/public_html/wp-content/plugins/paypal_file_download/paypal_file_download.php:48 Stack trace: #0 /home/revoluti/public_html/wp-content/plugins/paypal_file_download/paypal_file_download.php(12): PayPalFileDownload::init() #1 {main} thrown in /home/revoluti/public_html/wp-content/plugins/paypal_file_download/paypal_file_download.php on line 48