certificate error ?

[alfred hitch]

Hi,

I am trying to configure wpa-radius  and while passing certifcate file
I am getting error at time of authentication :

Jan 01 11:33:47.952348: TLS: Certificate verification failed, error 20
(unable to get local issuer c
ertificate) depth 0 for
'/C=SG/ST=SG/L=SG/O=SG/OU=SB/CN=SB/emailAddress=admin'


Do I need to put something else also ? or is this wrong certifcate ?

Cheers,
Alfred