The app can't start after Upgraded by UART dfu ?


     I transfer the init packet and firmware to bootloader successfully by UART DFU, and then  the app can not start. It report error as below:

<00> info> app: Inside main
<00> info> app: lfclk config finish!!
<00> debug> app: In nrf_bootloader_init
<00> debug> nrf_dfu_settings: Calling nrf_dfu_settings_init()...
<00> debug> nrf_dfu_flash: Initializing nrf_fstorage_nvmc backend.
<00> debug> nrf_dfu_settings: Settings OK
<00> debug> app: Enter nrf_bootloader_fw_activate
<00> debug> app: Valid App
<00> debug> app: Enter nrf_dfu_app_continue
<00> error> app: Received a fault! id: 0x00004002, pc: 0x00000000, info: 0x20004FE0
00> eived a fault!

I have no idea, please tell me how I can debug this error!!

Thanks very much!!

Best Regards!!