MS428 Reset FRP Lock Failed

Checking data…OK
Platform: LG Qualcomm
Selected port: COM144
Selected model: MS428
Please, put the phone into download mode manually (Power phone OFF, press and hold "Vol+" button and connect the cable (or P990 cable)).
Reading info…
Model ID: LGMS428
IMEI: 358479-07-XXXXXX-8
Android version: 6.0.1
Battery level: 69%
Mode: Emergency
Initializing flash…OK
SW version: LGMS428AT-02-V10c-310-160-MAY-19-2016-ARB01+0
LAF Version: 1.1
Product ID: CH31S160426001924
IMEI: 358479-07-XXXXXX-8
Target operator: MPCS
Hardware: rev_10
Reading partitions…OK
Resetting FRP Lock…Failed!
Performed by 2.3.9 software version.