Samsung g930f oreo failed to unlock

I have a samsung s7 G930F failing to network unlock.What could be the solution here

Waiting ADB device... OK
Reading phone info...
Model: SM-G930F
Android version: 8.0.0
PDA version: G930FXXU5ESD2
CSC version: G930FEVR5ESD2
Phone version: G930FXXU5ESD2
Product code: SM-G930FEDAEVR
CSC country code: UK
CSC sales code: EVR
Phone SN: R58J108FVSK
IMEI: ***************
HW version: MP 0.700
RF cal date: 20161230
Chip name: EXYNOS8890
Modem board: SHANNON335
Security patch: 2019-05-01
Boot Warranty bit: 1
SIM State: NETWORK_LOCKED
Checking Super user right... true
Reading NV data... OK
Checking NV data... OK
Reading data... OK
Detecting MODEM... OK
Reading MODEM... OK
Calculating... OK
Writing zTool... OK
Initialization zTool... OK
Running zTool, please wait... OK
Reading data... error (1)
Initialization zTool... error (0 1)
Try downgrade modem if possible

Done with Samsung Tool PRO v.36.1