Connection fail for Apache LDAP Authentication - apache

Question

I'm trying to let my Apache2 docker box(Ubuntu based) works with AD authentication, but I'm getting the error message
Fri Nov 18 14:59:38.508164 2016] [authnz_ldap:debug] [pid 2906:tid 140020857906944] mod_authnz_ldap.c(516): [client 192.168.56.1:61467] AH01691: auth_ldap authenticate: using URL ldap://192.168.56.150/CN=Users,DC=comp,DC=local?sAMAccountName?sub?(objectClass=user)
[Fri Nov 18 14:59:38.508181 2016] [authnz_ldap:trace1] [pid 2906:tid 140020857906944] mod_authnz_ldap.c(537): [client 192.168.56.1:61467] auth_ldap authenticate: final authn filter is (&(objectClass=user)(sAMAccountName=testuser01))
[Fri Nov 18 14:59:38.508350 2016] [ldap:trace5] [pid 2906:tid 140020857906944] util_ldap.c(329): [client 192.168.56.1:61467] LDC 7f593ab9e0a0 init
[Fri Nov 18 14:59:38.548846 2016] [ldap:trace5] [pid 2906:tid 140020857906944] util_ldap.c(186): [client 192.168.56.1:61467] LDC 7f593ab9e0a0 unbind
[Fri Nov 18 14:59:38.549037 2016] [authnz_ldap:info] [pid 2906:tid 140020857906944] [client 192.168.56.1:61467] AH01695: auth_ldap authenticate: user testuser01 authentication failed; URI /repos [LDAP: ldap_start_tls_s() failed][Connect error]
[Fri Nov 18 14:59:38.549047 2016] [core:trace3] [pid 2906:tid 140020857906944] request.c(119): [client 192.168.56.1:61467] auth phase 'check user' gave status 500: /repos
[Fri Nov 18 14:59:38.549088 2016] [http:trace3] [pid 2906:tid 140020857906944] http_filters.c(1006): [client 192.168.56.1:61467] Response sent with status 500, headers:
As you can see my AD server IP is 192.168.56.150. STL force enabled, Apache configuration is:
<VirtualHost *:80>
ServerAdmin webmaster#localhost
LogLevel trace8
ErrorLog ${APACHE_LOG_DIR}/svn-error.log
CustomLog ${APACHE_LOG_DIR}/svn-access.log combined
<Location / >
DAV svn
SVNParentPath /var/www/svn
SVNReposName "Subversion Repository"
AuthBasicProvider ldap
AuthType Basic
AuthName "AD Authorization Realm"
AuthLDAPURL "ldap://192.168.56.150/CN=Users,DC=comp,DC=local?sAMAccountName?sub?(objectClass=user)" STARTTLS
AuthLDAPBindDN cn=coops,cn=users,dc=comp,dc=local
AuthLDAPBindPassword 123456
Require valid-user
Require ldap-group CN=developers,CN=Users,DC=comp,DC=local
AuthLDAPGroupAttribute member
AuthLDAPGroupAttributeIsDN off
</Location>
</VirtualHost>
LDAPTrustedMode STARTTLS
LDAPVerifyServerCert on
LDAPTrustedGlobalCert CA_BASE64 /etc/apache2/certs/caroot.crt
I'm able to access AD from some LDAP client.
Anybody knows why my Apache server doesn't work?