how to resolve this problem:
Process completed with ERRORS.
***Wait for reboot to confirm the SIMLock status.[Reasons]
1. ChallengeData is missing in server response
***Hints***
1. Check your Internet connection.
2. If problem persist, contact the admin.
Updating devices list. Done!
Updating devices list. Done!
Updating devices list. Done!
SIM Unlock Failed
*HINT: Please reflash it using LumiaRecoveryTool and try again the unlock procedure.
Updating devices list. Done!
Updating devices list. Done!
Connecting to device...
Application info
Version 4.3
Copyright © 2016
Created by dk
Enjoy it ;-)
Loading device info (Client Version 4.3). Done!
***Device Info
Model: Nokia Lumia 820 (RM-825)
Sw Version: 3051.50009.1424.0015
Product Code: 059Q9Q0
IMEI: 354105052759080
NETWORK LOCK: ACTIVE