Fatal error: Uncaught Error: Class 'phpseclib3\Crypt\Common\StreamCipher' not found in /var/www/dsmailer/modules/dsmailer_campaigns_managment/server-side/phpseclib3/Crypt/RC4.php:56 Stack trace: #0 {main} thrown in /var/www/dsmailer/modules/dsmailer_campaigns_managment/server-side/phpseclib3/Crypt/RC4.php on line 56