Looks like your router is having problem. If the SSID is not shown at all you might want to exchange your router. D-Link has lifetime warranty. They can do a one to one exchange for you.
SSID shows now but any configuration of wiring that used to work previously now does not work at all
I mean I can connect to the SSID but there is no connection, even if directly connected to the provided router and then to the DIR-655 and finally to the computer.