g950u Calculating... error (0) cnot unlock

hi
i try to unlock but cnot calculation any idea please?

Operation: Unlock
Selected model: SM-G950U
Selected port: COM74 SAMSUNG Mobile USB Serial Port
Software version: 33.7

Checking Login and Password... OK
Ballance: 40 crd.
You have 40 credit(s) left. This operation takes 10 credits.Continue? Yes
Waiting ADB device... OK
Reading phone info...
Model: SM-G950U
Android version: 8.0.0
PDA version: G950USQU5CRG3
CSC version: G950UOYN5CRG3
Phone version: G950USQU5CRG3
Product code: SM-G950UZKATMB
CSC country code: USA
CSC sales code: TMB
Phone SN: RF8K52L9TRT
IMEI: 353xxxxxxxxx6
HW version: REV1.0
RF cal date: 2018.05.23
Chip name: MSM8998
Modem board: MSM8998
Security patch: 2018-07-01
Boot Warranty bit: 0
Searching Samsung diag port... detected COM74
Reading phone info... OK
Reading data from phone... error (0), skip
Waiting for device to become ready... 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 from phone... OK
Rebooting to upload... OK
Searching Ramdump interface... COM76 detected
Reading data from phone... OK
Calculating... error (0)

Done with Samsung Tool PRO v.33.7