The Additional Security Certificates File

A shared web hosting server maintained by a web hosting company should normally have its Certificate Authority data updated automatically. However, if you run your own server, or use a package like Xampp, you might see this error when you test your PayPal account.

If you see this error, you need to download the file "cacert.pem" from here:

https://curl.haxx.se/docs/caextract.html

Copy the cacert.pem file to the root directory of your site. Payage will find it and load it whenever it connects to PayPal.