Yellow/blue LED flash means the openSPOT2 is connected to your Wi-Fi network, and it's trying to connect to the selected server:
http://manuals.sharkrf.com/openspot2/en/led-states.html
Probably the server you are trying to connect is down. Try using another server, and/or see the Troubleshooting section of the user manual:
http://manuals.sharkrf.com/openspot2/en/troubleshooting.html