vCAC Register problem on Application Director 6.0

I tried to register vcac 6.0 on Application Director 6.0. I got this error.

register-vcac-server --componentRegistryUrl https://172.28.x.x --ssoAdministratorUsername administrator@vsphere.local --ssoAdministratorPassword xxxxxx --tenant vsphere.local

Registering vCAC server, this will take few moments..

[ERROR] Invalid SSO Admin credentials.

SSO admin password is correct.  Could you help me this issue