Cannot make my phone work after flashing a stock ROM (Bootloop)

[FranMatsusaka]

I was trying to downgrade firmware to be able to root the device as it explains in this thread:

[XZ1c/XZ1/XZp] temp root exploit to backup drm keys implemented

Tools to backup TA partition (drm keys) of Xperia XZ1 Compact by j4nn https://j4nn.github.io/ As everyone knows, bootloader unlock via code from sony removes drm keys. That disables certain functions, the most critical one being the camera...

forum.xda-developers.com

I downloaded the 47.1.A.8.49_CE1 firmaware, and I flashed to the phone (removing all .ta files and user_XXX.sin files), and what I got is a bootloop... I tried other stock ROM and with the same result. In the desesperation, I may flashed user data, so maybe DRM key is forever gone, but I cannot say for sure... I don't know what I'm doing wrong, at this point I don't mind to lose the DRM key or if I have to instal a custom ROM. Any help would be really apreciated. I tried EMMA but it says the phone is bootloader is locked.

 

[FranMatsusaka]

I was able to recover the phone by flashing a modern firmware... DRM keys and personal data were safe. To do a downgrade a factory reset is mandatory?

 

[FranMatsusaka]

Te problem now is that I cannot use WiFi anymore. It disables instantly every time I enable it. Another problem is that I can't use the digital sensor anymore. I have tried two different firmwares with the same result.

Maybe I should try to flash a custom firmware? Downgrading seem a little bit difficult to me, so if I unlock the bootloader losing the drm keys in the provess, that won't be a problem for custom rom, isn't it?