New protocol adapter gives message on my ap “Gateway Not found”

Hi. To get help, you'll need to provide much more information: equipment description, what was changed, exactly what you're doing, and where the error appears. Pictures, screen shots, etc. help a lot. "Protocol adapter" is pretty meaningless by itself. "Gateway not found" is a typical message that all electronic equipment gives when it's failing to connect to a network. The gateway is the first thing on the wire or wireless route that it can talk to.