This error results from missing email addresses. In order to import users to EZOfficeInventory with the LDAP integration, each user needs to have a last name and an email address associated with them. EZOfficeInventory uses email addresses to identify unique users in its database. In addition to this, email addresses are often the LDAP login attribute.
To avoid the import error, add an Email attribute for every new user that you create in your LDAP environment.