NOT WORK.. On XDA thread is using MRT dongle, without that its impossible .. using spftool/flashtool is useless wasting your time, coz the bootloader is Locked..
for fix that problem.. go to service center on your country ..
my device fixed with repair Emmc .. need Rp.200.000,- to fix that.
coz in my town there was No Service Center of Meizu..
Permanently closed on Google.. in Bandung
So be careful if u want to update your Os version ..
Os version is suck.. on M3 Note,M2Mini, U20..