RESET PIN cause a HardFault_Handler

[MR.liu]

When I operate RESET PIN in main function like this:NRF_POWER->RESET = 1,Then cause a HardFault_Handler,(/attachment/fabd1141d36157d32f8c0353e4880b3e),What's this？

[MR.liu]

the program is normal when I calling opt_reset_func() as the first function in main,That's why？