An error "Unable to get local issuer certificate" can be displayed when installing October CMS. The complete error may read cURL error 60: SSL certificate problem: unable to get local issuer certificate.

Solution

Download this certificate file and save it as cacert.pem. Open your php.ini file and insert or edit the following line. You may need to restart Apache for the change to take effect.

curl.cainfo = "/path/to/cacert.pem"

Note: SSL connection problems are also the most common issue when using remote services, such as Amazon S3 with the Media Manager. If you get SSL errors, make sure that your server has fresh SSL certificates of public Certificate Authorities (CA).