DIAGNOSIS Error E195 indicates no power from the 'Rh' wire, which is the 24VAC heating power feed. Your system is not providing the necessary voltage.
FIX Remove the display. Check the red 'Rh' wire is securely in its connector on the base. Ensure the wire is not damaged or loose at the furnace control board. Re-seat the display.
IF THAT DIDN'T WORK The 24VAC transformer in your furnace may have failed or a safety switch (like a flame rollout or high-limit) is open. You will need to check for 24VAC between Rh and C at the furnace control board with a multimeter.
HEADS UP If you have a zoned system, the zone controller may be the source of the power interruption, not the main furnace transformer.