PLD on Breadboard Programming WARNING!
Do NOT program your DE10-lite PLD board while the board is connected to anything (other than power and ground) on your breadboard, i.e., remove input and output connections from/to your circuit (switches, LEDs, etc.) before programming or reprogramming.

The reason that we do this is as follows. Imagine that you have an old design still wired up to your PLD and then you reprogram with a new design. If the old design had a pin assigned as an input and the new design uses that same pin as an output, then BOOM! The pin will likely be damaged.