Obviously I’ve not seen your installation, but here are a few ideas.
Disconnect the genny and try something electrical direct from it. If it works then genny ok, if it doesn’t work then genny at fault. Does the genny have a cut out button or switch for overload or short circuit ? If so reset and try again. If working reconnect to system. If now recharging then all ok. If not recharging ask Nigel to return and possibly reset the parameters for the inverter.
Hope this helps/sorts it.
Steve