The switches that control those solenoids are not in the switch matrix. The pop bumpers and slings each have an additional switch which is "allowed to close" when the solenoid fires. It's the second switch that the game is complaining about. You may notice that there is no sound or points scored when you hit the pop bumper or slings. The fix is to adjust the switches so that they close when the solenoid plunger is pulled in.