FortiAP 221C not getting connected

Hi,

I have connected FortiAP 221C to Fortigate50E  . LAN connection is fine . and i have created SSID too. 

Then in Managed FortAPs session I have done with all the settings and try to refresh . I clicked on Authorise button also . But the WiFi LEDs are not blinking and i can see that  it is not getting connected to any device in the network. 

WHat might be the issue