SAMSUNG J710F DRK Repair failed

Hellow team, i've tried to repair DRK for my J710F with latest setup 33.2 but the result is as follow...

Checking local file... OK
Searching server... not found
Searching USB Flash interface... COM14 detected
Setup connection... OK
Reading data from phone... OK
Sending data to phone... OK
Sending data to phone... OK
Waiting ADB device... OK
Reading phone info...
Recovery build version: 6.0.1
Boot version: J710FXXU5BRC2
Platform: exynos7420
Boot serial: 52034b11f0359425
Product board: j7xelte
Initialization zTool... OK
Running zTool, please wait...
Start... OK
Initialization... OK
Generate and check client proof... OK
Verify proof by client... OK
Checking DRK status... NG!
Writing DRK... error ()

Done with Samsung Tool PRO v.33.2

any help will be appreciated