Share your experience!
try to run Xperia Diagnostics..to see if the sensor will pass the test
try to make a call while on safe mode
try perform a software repair using Xperia Companion.
if all else fails send your device to your local service center for repairs Local support
Does your phone has a protective case, film and/or glass? is there anything covering or partially covering the proximity sensor?
I'm having a similar problem, Whenever I try to call anyone, screen suddenly goes blank although call will go through but I won't be able to select anything on screen. Screen remains blank till the call is disconnected from the other side, can't even disconnect from my end. Something is seriously wrong with proximity sensor after this latest formware update. Any suggestions to sort this out??