g935t unlock error

Operation: Unlock
Selected model: SM-G935T
Selected port: COM23 SAMSUNG Mobile USB Serial Port
Software version: 37.0

Checking Login and Password... OK
Ballance: 9 crd.
You have 9 credit(s) left. This operation takes 8 credits.Continue? Yes
Waiting ADB device... OK
Reading phone info...
Model: SM-G935T
Android version: 8.0.0
PDA version: G935TUVSACSG1
CSC version: G935TTMBACSG1
Phone version: G935TUVSACSG1
Product code: SM2G935TZDATMB
CSC country code: USA
CSC sales code: TMB
Phone SN: RF8H92BE54H
IMEI: 356164074992870
HW version: REV0.7
RF cal date: 2018.11.30
Chip name: MSM8996
Modem board: MSM8996
Security patch: 2019-07-01
Boot Warranty bit: 0
SIM State: READY
Rebooting phone... OK
Waiting ADB device... OK
Rebooting phone... OK
Waiting ADB device... OK
Waiting for device to become ready... OK
Initialization zTool... OK
Running zTool, please wait... OK
Reading data from phone... OK
Rebooting to upload... OK
Searching Ramdump interface... COM97 detected
Reading data from phone... OK
Calculating... OK
Searching server... OK
Waiting for server answer... error (1)

Done with Samsung Tool PRO v.37.0

anyone help me?