when i verify commercial certificate
[root@zimbra]# /opt/zimbra/bin/zmcertmgr verifycrt comm /opt/zimbra/ssl/zimbra/commercial/commercial.key /tmp/commercial.crt /tmp/bundle.crt
** Verifying /tmp/commercial.crt against /opt/zimbra/ssl/zimbra/commercial/commercial.key
Certificate (/tmp/commercial.crt) and private key (/opt/zimbra/ssl/zimbra/commercial/commercial.key) match.

XXXXX ERROR: Invalid Certificate: /tmp/commercial.crt: C = , postalCode = , ST = n/a, L = , street = St., O = example , OU = PremiumSSL, CN = zimbra.example.com
error 20 at 0 depth lookup:unable to get local issuer certificate

where is the problem?