configuring

I've just gone from the factory firmware to 11.2 and have a couple of questions on the settings I was hoping people could help me with, note I did a reset to factory defaults... Is there any way to load in an exported Client list, as I only see an Export button (do I have to type all the names...

Every time I try to insert an IP into the DHCP list, it gives the following error: How to Fix It? Note 1: No equipment in the DHCP list has access to the network or the internet. Note 2: I have already reset the router to the factory settings. Note 3: I tested with Firmware 384.6, 384.7...