ldap_sasl_interactive_bind_s: No such attribute (16)

[Robin SP Zhang <RobinZhang@pek.destiny.com.cn>]

Hi,
     I set up openldap server and client with TLS, then if I search with
ldapsearch -a always -x -h 10.16.110.102 -b "dc=SGI,dc=US" -s one
objectclass=*,
then I can get all entries in server. but if I search with 
ldapsearch -a always -Z -h 10.16.110.102 -b "dc=SGI,dc=US" -s one
objectclass=*,
then I can not get any except for
ldap_sasl_interactive_bind_s: No such attribute (16)

also, if I search supportedSASLMechanisms with 
ldapsearch -h 10.16.110.102 -p 389 -x -b "" -s base -LLL
supportedSASLMechanisms
no result returns. 

so I think  there is some configuration error in slapd.conf,

who can help me?

thanks in advance.

Robin Zhang.