Well. It's more complicated than that. My kernel is naa latest version. I cant go in recovery mode. It stucks in grey screen with no options on when i press the back button. i will try to flash stock kernel and rom but iam not sure it will work. Its weird that i cant go in recovery mode. Plus that when i use flashtool i cant moderate anything else in my phone because computer or usb doesnt recognise the model. i will try update via sony and let you know. If you have any new suggestions post here. Otherwise i will buy a new phone soon.