Hello,I have flashed my phone several times between 5.2.4.0G and betas. But for several weeks, my phone is unstable even after a factory reset and flash update.zip 5.2.4.0G.
I still have problems, especially on the network (3G / 4G, wifi and bluetooth).
I often have to reboot to temporarily fix connectivity issues.
So I try to totally reinstal my phone from scrath.However, I can't format the system partition via fastboot (by booting in fastboot mode) :
# fastboot format system
Creating filesystem with parameters:
    Size: 2684354560
    Block size: 4096
    Blocks per group: 32768
    Inodes per group: 8192
    Inode size: 256
    Journal blocks: 10240
    Label:
    Blocks: 655360
    Block groups: 20
    Reserved block group size: 159
Created filesystem with 11/163840 inodes and 21489/655360 blocks
target reported max download size of 134217728 bytes
erasing 'system'...
FAILED (remote: Permission Denied!)
finished. total time: 0.044s

Do you have an idea to format the partitions of my Meizu Pro 6, to come back in version 5.2.4.0G, as out of this box.Thank you in advance for your help.