Multiplus-II 2x120 Inverter Not Working

Multiplus-II 2x120v 3000. Inverter will not work, but lithium battery power getting to the unit. No lights when turned on. However, passthrough for generator and shore power works and lights on unit are on. Any ideas?

Is the switch in the ‘on’ position and not the ‘charge only’ position?

Actually, I got it resolved, but not sure how. I disconnected all battery power to the system and turned it back on. But the switch may have been in the wrong position. I never start with the east fix. Thanx for your response.