Share your experience!
does this happen when you are on safe mode?
if you recently updated your device you can try software repair using Xperia Companion
Hi @saleh66,
I'm sorry to hear about that. 
Was there any change when the phone was rebooted in safe mode like @nolramlb suggested?
What is the exact error message that you see on your screen? Does it say "Settings has stopped"?
If you see this error message, go to Settings > Apps > 3 dots > Show system > Settings > Storage > Clear data.
If that doesn't work, could you either provide me with a screenshot or type exactly what the error message is, I will make sure to assist you in the best possible way. To take a screenshot, press and hold the ON/OFF button > Take screenshot.
Let me know how it goes! 
Hi again!
I'm glad to hear that everything is working again and thanks for telling me about this!
Let me know if there is anything else and have a great Tuesday!