[eluser]dale88[/eluser]
what i did was i created a cert folder outside system folder. In there i placed all the certificates then i configured .htaccess to redirect the cert folder to index.php. So the script should like the one below. Don't put base_url() otherwise it won't work
$paypal->setUserCertificate("cert/public-cert.pem", "cert/private-key.pem");
$paypal->setPaypalCertificate("cert/paypal_public_cert.pem");
$paypal->setPaypalCertificateID("7GU38MNDJEGM8");