DFU not working

  • DFU not working,

    i follow the steps mention in the documents.
    1) download micro-ECC file
    2) generate private key using nrfutil command
    3) generate public key & place in my workspace.
    when i was trying to generate .ZIP file using
    ( nrfutil pkg generate --hw-version 52 --sd-req 0 --sd-id 0xb7 --application-version "2.0.0" --application ble_app_uart_pca10100_s113.hex --key-file priv.pem app.zip )

    its succesfully generate . but when i was send OTA using nrf tool its show me invalid object

    or else if i change the softdevice id or change the command , my zip file not generate.

    B] is it any problem related to bootloader or mbr

    C] and how to change the bootloader address and how to store this address in MBR.

  • I am use secure bootloader example.

    code successfully execute ,its also start advertising  ( dfu_targ ) .but zip not generate properly and if I have use already available image,

    and send OTA my device show invalid object or advertising timeout  .

    I haven't find out what is the main problem pls help me.