This is my xml .. I dont see any missing tags here ..
property name="configurators">
<list>
<bean class="org.activiti.ldap.LDAPConfigurator">
<property name="server" value="xxx" />
<property name="port" value="xxxx" />
<property name="user" value="xxxx" />
<property name="password" value="xxxxx" />
<property name="baseDn" value="DC=xxxx,DC=xxxxx,DC=xxx" />
<property name="queryUserByUserId" value="(&(objectClass=person)(sAMAccountName={0}))" />
<property name="queryGroupsForUser" value="(&(objectClass=group)(member={0}))"/>
<property name="userIdAttribute" value="sAMAccountName" />
<property name="userFirstNameAttribute" value="givenName" />
<property name="userLastNameAttribute" value="sn" />
<property name="groupIdAttribute" value="cn" />
<property name="groupNameAttribute" value="cn" />
</bean>
</list>
</property>