The issue here is that we are using an SSL certificate chain which is reliant on a relatively recent CA (certificate authority). In order for SSL to work your computer needs to have a list of trusted CAs and the lists on these operating systems are woefully out of date.
When the script attempts to fetch the download from our server it fails because the operating system doesn’t have updated CA information. This is usually provided as part of a regular operating system update, but in the world of Linux devices the delivery mechanism and cadence is all over the map.
Long and short is that you need to look to your OS provider for an update. This isn’t an issue with Roon or our install script. It’s a problem with the operating system on your server.