RealVNC incompatible with screen sharing

Hi all,

We have a RealVNC license which we use for our Windows boxes and VMs. I would like to use ARD to control and observe these along with my Mac clients, but for some reason when I set up an entry as specified in the manual, I get the error "Connection failed to [computer]. The software on the remote computer appears to be incompatible with this version of Screen Sharing." This happens with both ARD and the built-in VNC client. I don't understand how it wouldn't be compatible, as it is just a standard VNC server. I have the latest version of ARD running on Yosemite.

Any suggestions?

Thanks!