After you create the VLAN, under Interfaces -> VLANs, which it looks like you did correctly, you need to assign it to a valid physical interface. That is done under Interfaces -> Interface Assignments. So, in your examples, you've created VLAN 160 on your LAN interface. After this gets setup, you should be able add the VLAN as an interface, under the dropdown "Available network ports". You've got a photo of it, but your picture says "ovpns1 (OpenVPN)". Is there anything else under that dropdown menu. The VLAN in question should be an option in there. Jeff