This problem just started in the last week or so. My network configuration is as follows – Airport Extreme --> Powerline communication --> Airport Express (kitchen) via Ethernet from powerline Same Airport Extreme -->ethernet cable --> Airport Express (basement). The Airport Expresses are set to create wireless network and DHCP is set to off. This has been my configuration for at least six months and has worked with no issues. In the last week I have been having an issue where when the MacBook in the kitchen is turned on the, kitchen Airport gets kicked off the network (In the utility it has the yellow triangle with exclamation point) and the MacBook won’t connect to the network. If I unplug the power line adapter, the MacBook instantly connects to the Wifi. Once the Airport Express comes back up it stays online, until the next time the MacBook starts up. I assumed this was being caused by some sort of IP conflict, so I setup an IP reservation for every device in the house including the two Expresses. This did not resolve the issue, so I deleted the reservations for the Expresses. Issue resolved….for three days. Now it’s happening again. This issue only occurs when the MacBook comes online. We have multiple other wireless devices (phones, tablets, rokus, TVs, PS3), none of them cause this issue. Any ideas?