Do yo have VLANs 10,11,12,13,14,15,16,17,18,19,20 trunked to all of your access points? If not, you should really have only the VLANs you have trunked, separated by commas. The difference between Instant and the Controller is that if you put 10-20 on the controller, the controller will only trunk users to VLANs that are already assigned on the controller. In Instant there is no way to define VLANs ahead of time, so you should simply use commas to separate each VLAN instead of a (-)