No DFU board found(BlueNRG-1 EVK)

[shakk.1]

HW: ​BlueNRG-1 development platforms (order code: STEVAL-IDB007V1)

GUI: BlueNRG4.4

I followed um2071-bluenrg1-bluenrg2-development-kits-stmicroelectronics to try to upgrade the firmware.

the LED2 is flashing.....buf upgraded fail.

Is there any wrong or missing about my opreation? thanks!