fail read nv samsung sgh-i897 with hua tools

IMPORTANT NOTE: DON’T CONNECT MULTIPLE ANDROID DEVICE IN USB DEBUGGING MODE AT SAME TIME!
Waiting For Device… OK[WinUSB]
Device Status: [ONLINE]
Checking Root Permission… OK
Prepairing NV… OK..OK
—–> Backup NV(1)… Fail! -4
Stopping ADB Service… OK
Operation Time: 00:00:55