It is possible on the display for a D to looks similar to an O. You probably have a DE error code which indicates a drain problem.
Check your drain line, make sure the drain hose is not kinked and is not blocked especially at the connection to the sink or garbage disposal. This is typically the reason that a dishwasher won't drain. Remove the hose and clear any clogs, then reinstall.
Verify that water from the sink drain is not making it's way into the dishwasher. I would recommend creating a high loop in the dishwasher drain pipe, which is attached to the sink drain below the sink. The high loop can be fastened to underneath the counter-top. This will prevent any water from entering the dishwasher from the sink; it also prevents the dishwasher drain water from making it's way back into the dishwasher.
Verify that the pumps drain impeller is working. You can reach the impeller from inside the dishwasher after removing the lower rack, spray arm and arm support. This typically involves removing a few screws. Once upper parts are removed, inspect the drain impeller (which pushes the water toward the drain port) for any cracks or missing blades. If the impeller is defective the water will not drain properly and you would need to replace it.
Verify that the drain valve is working; many are controlled with an electric solenoid that opens the valve, sending the water to the drain. There is a chance that the solenoid or the diverting lever could be stuck which would prevent the water to drain. If so, try to free up the solenoid and lubricate the lever. Otherwise the solenoid or pump assembly may have to be replaced.
Verify that the motor is turning/ working and that there is power to the motor. If the motor hums but doesn't turn, it may need to be replaced. Motors can get stuck if not used regularly. If the motor is defective, the water will not drain and you would need to replace it.