Xperia Z3 reset after upgrading to lollipop

[RCV]

I upgraded to lolipop about a month back and my phone got factory reset ( lost all data from my phone , sdcard , sim ) and prompted for new set up installation. This happened while i was out , and my phone was in my pocket once and another time when i was in at work , lost all data both the times and i couldnot find any trace of what triggered the wipe off button on my phone , can some one help me ?

[Qatrium]

There is one user with Xperia Z1 compact reported this problem. He replaced his SIM card from carrier and the problem was resolved. Consider trying this.
/t5/Xperia-Z1-Compact/Z1-compact-factory-reset-by-itself/td-p/653725