title: CodeIgniter 3 Auth_Ldap Library Couldn't find groups: Operations error
body: <p>I'm trying to authenticate users using an Auth_Ldap library, in CodeIgniter 3, but I'm getting the following errors:</p>
  <blockquote>
  <p>A PHP Error was encountered Severity: Warning</p>
  <p>Message: ldap_search(): Search: Operations error</p>
  </blockquote>
  <blockquote>
  <p>A PHP Error was encountered Severity: Warning</p>
  <p>Message: ldap_get_entries() expects parameter 2 to be resource,
  boolean given</p>
  </blockquote>
  <p>The second one it's because ldap_get_entries() expects the second parameter, and this is the $search, who depends on ldap_search.</p>