DigitalInputPullup example sketch causes conflict on USB bus and crashes Mac

Hello to and thanks so much to whoever is reading this:

Arduino board: Nano 328

After I uploaded the builtin example File->Examples-> Digital -> DigitalInputPullup , my nano board's TX led is stuck ON, and each time I try to reprogram it via USB, it crashes my Mac computer.

I also tried using another nano board as ArduinoISP to overwrite the troubled program, but programming also fails.

I have 2 questions:

  1. Is there something wrong with the builtin DigitalInputPullup sketch?
  2. How can I erase the bad programming on my nano boards?

Any help would be appreciated.
Thank you

Burt1:
After I uploaded the builtin example File->Examples-> Digital -> DigitalInputPullup , my nano board's TX led is stuck ON, and each time I try to reprogram it via USB, it crashes my Mac computer.

Probably a "post hoc ergo propter hoc" fallacy.

Burt1:
I also tried using another nano board as ArduinoISP to overwrite the troubled program, but programming also fails.

Clear evidence the problem is unrelated to the DigitalInputPullup sketch.

Burt1:

  1. Is there something wrong with the builtin DigitalInputPullup sketch?

No

Burt1:
2) How can I erase the bad programming on my nano boards?

There is no bad programming. You can erase the program on the board by uploading a new program, but first you need to figure out why the IDE is crashing.

When you do an upload the sketch is first compiled. So you can narrow down the cause of the problem by determining whether the crash happens during compilation. So just compile a sketch in the Arduino IDE by doing a Sketch > Verify/Compile.

Is it a ch340g based nano? Have you installed the new drivers? The old drivers started crashing with a recent OS update