Hope you will get some help from below Link
The SSL certificate error you're encountering when importing the Swagger definition into ReadyAPI is commonly caused by issues with the SSL certificate's validity or configuration. Even though you've followed the suggested solution of trusting all certificates using the -Dio.swagger.parser.v3.util.RemoteUrl.trustAll=true option, it’s essential to ensure that the server’s SSL certificate is valid, not expired, or self-signed. If using a self-signed certificate, you may need to manually import it into the Java keystore. Additionally, double-check for any firewall or proxy settings that might be interfering with the connection. While changing the URL to HTTP instead of HTTPS can provide a temporary workaround, it should be avoided in production due to security risks. Lastly, make sure you're using the latest version of ReadyAPI, as newer releases often fix SSL-related issues.
