Issue with SEPM 12 - SEP 11.0.7 clients will not auto-upgrade

Hi,

I have recently upgraded my company's SEPM environment from SEPM 11.0.7 to SEPM 12.1.2015. Everything seems to be working fine with the upgraded SEPM server, and I can manually deploy SEP 12 to clients, but when I create an install package for SEP12 and assign it to a particular group, those clients in the group will not auto-upgrade to SEP 12. The auto-upgrade feature worked perfectly on the SEPM 11.0.7 environment.

Can anyone help?