File does not exist photon.loadbalancing.dll.config

Hey all

Just a quick question, trying to set my ip for to local ip using the Game server IP Config > Set Local IP...

every time i try i get confronted with

File does not exist:
..\Loadbalancing\GameServer\bin\Photon.loadbalancing.dll.config

When navigating to this file it does exist. I have set the ip config previously in the past but has stoped allowing me to do so the last couple of days

Thanks for any help