RNE-L21 Flashing Problem

SigmaKey v.2.29.05
421098412 Sigma dongle 2.29, Initializing...OK
Pack 1: Activated
Pack 2: Activated
Pack 3: Activated
--------- 2018-09-27 14:37:17 ---------
SigmaKey 2.29.05 HiSi: Write firmware
HUAWEI USB COM 1.0 (COM145), Provider: HUAWEI Incorporated, Driver ver.: 2.0.6.725, Date: 11/6/2015, USB\VID_12D1&PID_3609&REV_0100
Repairing...STFAL00S001050.skf
Sending boot....Error writing to serial port