As stated above, you get this message when the controller has not fully booted yet. I know it can sometimes take 10 minutes or so to fully reboot. Does it stay in this state until you reboot, beyond 10-15 mins, or if you give it enough time will it allow you to log in.
Also as stated, if you putty into it, you can watch it post each section of the boot process and see if an error occurs.