can't unlock zte Z716BL

SigmaKey 2.29.00b1 ADB: Direct unlock
* daemon not running. starting it now *
* daemon started successfully *
^ ZTE Handset ADB Interface
Version: Linux version 3.10.49-gf44e642 (wuyanling@ztesuper20) (gcc version 4.8 (GCC) ) #1 SMP PREEMPT Wed Jan 13 12:11:33 CST 2016
Phone model: ZTE Z716BL
Android 5.1.1; Firmware: LMY47V; Date: Wed Jan 13 11:59:45 CST 2016
Version: Z716BLV1.0.0B07
Baseband Firmware: O.1.1.c1.3-00007-8909_GEN_PACK-2
Baseband Processor: Qualcomm Technologies, Inc MSM8909
Removing firmware protection...Skipped
Preparing...........Data error