What is the difference between VSE version and Core version of Vyatta AMI

I create two instances on AWS, both of them are about Vyatta AMI, one is VSE6.7 version, and the other is Vyatta Core version.

I want to use HA cluster function, if I use the VSE6.7 AMI, I will get the error message, "Configuration path: [cluster] is not valid. Set failed", by typing "set cluster interface tun00" in configure mode. But it works on Vyatta Core version.

What is the difference between VSE AMI and Core AMI? Should I choose Vyatta Core AMI for cluster function? Is it supported on VSE AMI?

Thanks for your support :)