J710F FRP Reset, sboot downgrade

Platform: Samsung Android
Selected port: COM1
Selected model: SM-J710F
Operation: Reset FRP - UART EMMC
Searching for UART interface.. COM8
Connect Samsung Micro UART cable(with 525K resistor), press and hold "Vol-" + "Power" buttons for 15-20 seconds
Searching for device. Please wait...
Phone found.
Rebooting phone in Upload Mode...OK
Please connect phone to USB cable..
Searching for a phone. Please wait...OK
Reading data...
Checking operation...
This version of "sBoot" is not supported, try to downgrade "sBoot"!
Operation was failed!
Performed by 2.6.9 Software version.




which sboot can i use, i have the firmware J710FXXU5BRC2