Are you sure that you have the proper power from the shore connection? It would not be the first time that an outlet was miss-wired.
If you are sure about the outet...then I'd check at the transfer switch. If that is what you did, and you don't have voltage crossing that switch, it could be that it has just failed. It has to happen at some point, and today may have been your day.
Is there any sort of voltage protector in the system...that may have been fried or something?
If you don't plan to use the genset, you might be able to bypass the transfer switch, until you get a new one.