All you can do: Reflash 4.3 without wiping data etc..
Make a backup with the backup app from sony (backup to external SD)
Flash 4.1.2 and wipe everything.....
Boot up and restore backup..
Yaay . Two year member!
Device sent away for repairs to my USB Connector Will be back in two weeks!
I do not respond on techmail via the PM! Esspecially questions that can be found on the forum! Use search!