G4Fancy3DNucleus.cc uses no-break space (\u00A0) in exception description:
G4ExceptionDescription ed;
ed << "Nucleus Z A " << myZ << " " << myA << G4endl;
ed << "proton with eMax=" << eMax << G4endl;
and that character may not be present in other code page (e.g. chinese cp936), but I suppose that is not really important…