compatibility problems

[astemar]

Hello
I have some compatibility problems in Android Jelly Bean 4.1.2 with sim
Can I back two to Ice cream Sandwich 4.0.4

[Uliwooly]

which compatibility problems? how old is your SIM card? do you have the correct APN settings?

there are 2 options to downgrade

1) take it to a Sony service center

or

2) use flashtool

[Uliwooly · Accepted solution]

How to manually update, downgrade, root 2012 Xperias

http://talk.sonymobile.com/thread/41609