"Open Ground" from generator

i have had the same generator as yours for almost 2 years. great generator. our first TT was 30 amp with progressive ems 30amp system. had the same code. talked to champion tech support which is great. they explained why i was getting the code. bonding plug mentioned should work but honestly ive used the generator many times with no ems and never had a problem. YMMV is my disclaimer. the generator now runs our current TT which is 50 amp. 15k btu a/c even on propane (not in economy mode) with no problems. generator on gas will produce more wattage. we just don't run anyother high draw applicances like microwave at the same time.