Try the same using a REST tool.
As you can see, REST client says that SSL certificate is invalid and you have to import valid SSL certificates to proceed with REST / HTTPS.
Or you can try to ignore SSL validation on your REST client.
There are two ways to import SSL certs
1) Via menu Dashboard / Security / Certificates
2) Via command line https://flashphoner.com/docs/wcs5/w...ment-websocket_ssl-ssl_certificate_import.htm
Ok so I imported the keys successfully, the host:8888 now shows green https instead of crossed out red https which it was showing before, but a REST call to https://host:8888/RESTCall/call now returns 500 with empty body (no error message)