The gas is failing on proof of flame. This is most likely the thermocouple to the gas valve. Visually check the flame shape is complete. If distorted clean the orifice or burner tube. Once a complete flame is present check that the coupling is in the flame. If that checks loosen the coupler at the gas valve and reset it to ensure a good electrical contact.
If the electric side is tripping a breaker it is a short. Most likely the element has shorted. Disconnect the wires to the element and read each side of the element to ground with an ohm meter. The element should show open on both sides. If one side show a short replace the element.
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles