Might be this link is helpful:
http://www.cisco.com/c/en/us/support/docs/wireless/aironet-1200-series/100260-wlc-debug-client.html
DHCP_REQD—Controller needs to learn the L3 address from client, which is done either by ARP request, DHCP request or re...
Hi,
just an idea: one item to check is also on your switches if ip helper address is pointing to your DHCP server.
If the SSID are mapped to a VLAN, then check on your switches the vlan config for ip helper address.
Regards