I have a locked bootloader. My phone was RO ORANGE locked and branded, but I unlocked the phone using IMEI code to unlock.
I just changed the following codes to the vietnam ones
ro.semc.version.cust_revision (this was the same as the vietnam code).
after this line there was one about the branding of the phone: ro orange. i did not modify this line, maybe that's the reason the phone wouldn't start anymore.
after changing the region codes I tried to restart the phone, but only the sony logo showed up and the a black screen.
I flashed a FTF - [15.1.A.1.9], and then I updated my phone via PCC to the latest update 15.1.C.2.8.
I don't know what I did wrong in changing the codes. thank u for support