From your limited information, I assume you have a motorhome? If so, then with your house lights working when you're connected to shore power, then you are probably operating them on your Converter.
So, assuming your CUT-OFF switch is in the right position, then I would still say that your COACH batteries are not charged.
Remember, your power control panel that controls your 110-VAC systems, is powered by your 12-VDC COACH batteries, One of the things it does is sense when the generator is running and it turns your Transfer switch over to the generator from your external power.
So, check your Cut-Off switch first, then the solenoid the Cut-Off switch controls, then check that you have fully charged voltage (13.5-VDC) to your DC fuse panel, then the fuses.