Cisco AAA/Identity/Nac :: Compatible Nexus 5020 5.0.2.N2.1 With Tac Plus?

I have a problem with the switches Nexus, is impossible authenticate from tac_plus. In other company, I configured ACS for authenticate the Nexus Switches and OK The configuration of my tac_plus is:
 
user = gian {
login = cleartext prueba
member = nexus
group = nexus {
default service = permit
service = shell {
#double-quote-values = yes
#shell:roles=""network-admin""
cisco-av-pair*shell:roles="network-admin"
   
The configuration of switch is:
 
tacacs-server host xx.xx.xx.xx key 7 "xxxxx"aaa group server tacacs+ AAA_TACACS_SERVER    server xx.xx.xx.xx    source-interface mgmt0
aaa authentication login default group AAA_TACACS_SERVERaaa authorization commands default group AAA_TACACS_SERVER localaaa accounting default group AAA_TACACS_SERVER