If you have Gateways running firmware before v2.8, Manage does not communicate or commission them. To communicate and commission Gateways with firmware before v2.8, you need to do a few steps:
Step 1: Go to Administration > System Management.
Step 2: Click the Settings tab and scroll to Security Settings.
Step 3: Uncheck both the security options and click Apply.
Manage will then commission and communicate Gateways with firmware v2.8 or earlier and send notification messages if Gateways could not be commissioned. Retry commissioning the Gateways again.