Good advice here. Either a GFI has tripped-sometimes for no explainable reason or one of probably two little breakers has popped in the converter/inverter. I have had both happen for no reason that could be explained. If you have a inverter/converter combination unit like my Magnum or others there is usually two 15a circuits that go through the inverter and there are breakers for those circuits on the inverter. One of those circuits do what you have lost.
My tripped GFI was in the bathroom and had a little red light on that indicated it was tripped.
Jim