In the Source Server Authentication screen or the Target Server Authentication screen, if the option is not selected, then authentication to the server fails.
If you do not want to use a secure connection, deselect the option.
When this option is not selected, you must ensure that TLS is disabled for LDAP on the source server. Using iManager > > > > and deselect .
To use a secure connection, select the option (default setting).
When this option is selected, you must ensure that TLS is enabled for LDAP on the source server. Using iManager > > > > and select (it is selected by default).