The Google Chrome Team identified an issue with certificates created by Symantec and its other brands (GeoTrust, RapidSSL, Thawte). They mis-issued certain TLS server certificates. So all certificates have to be renewed accordingly.
You see this warning the browser as our CDN hosted player is distributed via Akamai, which is also affected by this issue. However Akamai is already aware of it, and in close contact with Symantec and Google and already prepared anything to update their certificates. At the latest until End of May 2018 this warning should be no longer visible.
More details about this issue and actions to resolve it are available here: