I just wanted to add, that by default there are two areas that limit to 100 clients, one is the AP itself, you can change this from withing the AP Group under model specific settings, and the other is as already described, in each WLAN/SSID.
So even bumping up the users per WLAN per AP setting under the WLAN settings still won't get you more than 100 clients on any specific AP until you increase the setting under model specific settings in the AP Group