SNMP v3 fails on Cisco WLC while using READ/WRITE

Folks,

I am trying to add my CIsco Wireless LAN Controller to NPM using SNMPV3 and wheni try to add a node i get the below error only when i fill in SNMP v3 READ / WRITE (bottom Box) the validate says test failed!!

but when i remove the bottom field and add my device using just the top box then everything works..

i have no clue what this second box read write SNMP cred is doing.. any insights will be helpful

Regards

Surendra