Halion 6 compatibility

Tried to install Halion 6 on to my main disk which runs Mac OS 10.6 (Snow Leopard) and it isn’t advanced enough. So rebooted in Yosemite but when I try to install Cubase on that volume, all seems OK. But when I try to run Cubase, I get a License Control Error: “No valid license detected for Padshop” When I try to click on [Cancel] or [Retry], the Cubase program locks up and must be Force-Quit. I have Cubase 4 and maybe it’s not compatible with Yosemite. Don’t have 10.9 to try.

Would I need to upgrade my Cubase in order to try Halion6? On a search of the discussions, It looks like there are problems with Cubase and Yosemite, but maybe that has been resolved by now. Looking for a way to check out Halion 6 - I do like HalionOne. Is there a way to do this other than buying OS 10.9 or upgrading Cubase?