samsung g935f unlock problam

Waiting ADB device... OK
Reading phone info...
Model: SM-G935F
Android version: 8.0.0
PDA version: G935FXXS3ERHD
CSC version: G935FOXA3ERGE
Phone version: G935FXXU3ARI1
Product code: SM-G935FZKABTU
CSC country code: UK & IRE
CSC sales code: BTU
Phone SN: RF8J609
IMEI: 35797308374
HW version: MP 0.801
RF cal date: 20170605
Chip name: EXYNOS8890
Modem board: SHANNON335
Security patch: 2018-09-01
Boot Warranty bit: 1
SIM State: ABSENT
Checking Super user right... true
Reading NV data... OK
Checking NV data... OK
Reading data... OK
Detecting MODEM... OK
Reading MODEM... OK
Calculating... OK
Initialization data... OK
Writing zTool... OK
Initialization zTool... OK
Running zTool, please wait...
Start... OK
Initialization... OK
Generate and check client proof... OK
Verify proof by client... OK
Reading data... error (1)
Initialization zTool... error (0 1)
Try downgrade modem if possible
Done with Samsung Tool PRO v.34.2