E:Unable to mount storage.
I have tried to re-flash TWRP. I have also tried flash the recovery.img from Google, and then flash TWRP. The problem still there.
I even try to nearly did a factory the full factory image by doing
fastboot flash bootloader bootloader-hammerhead-HHZ11d.img fastboot reboot-bootloader ping -n 5 127.0.0.1 >nul fastboot flash radio radio-hammerhead-m8974a-188.8.131.52.23.img fastboot reboot-bootloader ping -n 5 127.0.0.1 >nul fastboot flash system system.img fastboot flash boot boot.img fastboot flash recovery recovery.img fastboot erase cache fastboot flash cache cache.img and then restart phone,. booth into phone, and reboot to recovery and flash TWRP...