Could be lots of things, not much to go on here...is this a new installation (so it has never worked?). Or is it a working ZD1106 and when you added the 6 AP license then things broke?
What version of ZoneFlex is running?
What models of AP's do you have?
How are the AP's logically connected (same LAN, same VLAN, across a switch, routed, NAT'd, etc) to the ZD? Are you running across a tunnel or using MPLS?
If the ZD isn't seeing anything at all from the APs the most likely issue is L2/L3 connectivity isn't right.