I would first plug in the ethernet and establish that the hub will work with a hard wire connection
Also, your error message seems to be referring to the network key. Triple check you have the right key, and in fact, typed it into the Hub correctly. good luck ...
I seem to recall there might be instructions in the online help section for the Belkin N router. Did you try them?
To find them, I think you log into the hub web screens (where you can change pictures and such), click help on top right and look for startup help. They have a bunch of router specific instructions there.