Dear All

I have seen many thread like the one I am posting now but I couldn't find a cure ,,,,may be I overlooked or it is hiding somewhere on net I didn't find it
I am trying to set Netgear Nighthawk D8500 with Firmware Version V1.0.3.50_1.0.1 as an Access Point and I was looking to change the LAN IPs then this message popped up

400 Bad Request This server does not support the operation requested by your client
How can I overcome this issue ?