Hi Dao,
I am not sure if you are using TWR-K60D100M tower board do related test? If yes, you need to select to use TWR-K60N512 board, which is using K60 100MHz silicon 1.x product.
If you want to use related code with TWR-K60D100M board, you need to do some porting work, select the CPU component (MK60DN512VMD10 without 'Z' character).
I could run related code with TWR-K60N512 board without any problem.
Please check below attached serial terminal print info:

Thank you for the attention.
Best regards,
Ma Hui