Share your experience!
Hi @Anggia, welcome to our community!
I'm not quite sure what you mean. Do you set a screen lock (PIN/Pattern or password) and after a while it it's no longer needed to unlock your phone?
I would appreciate if you could elaborate a bit on the behaviour and I will do my best to assist you! 
Hi again!
I'm sorry for the late reply, Monday was a day off for me!
Oh, I see. Is it the application "Settings" that stops when trying to set the pattern screen lock in your phone?
You can upload a screen shot if you press reply > click on "Photos" which is located in the top row, next to "Insert/edit link".
If you get an error message saying that Settings has stopped. Go to Settings > Apps > 3 dots > Show system > scroll down and find Settings > Storage > Clear data.
Try setting a pattern screen lock again after doing this.
Let me know how it goes!
Hello, I have same issue and the above mentioned procedure didn't solve the problem. I can't use Android Pay without setting up the screen lock. What should I do ?
Hi @Adelinaa, sorry to hear about that. 
Have you tried to reset the Settings application that I advised @Anggia to try? If you haven't done that, I'd recommend that you try that at first and see if you are able to set a screen lock on your phone.
If there is no change, try rebooting your phone in safe mode and see if you can set a screen lock when third party applications aren't loaded.
Feel free to let me know how it went!
Hello, I have tried to reset the Settings, but it didn't work. Could you please advise how to enter Safe mode on M5, cause the instruction on the hyperlink is not valid for Xperia M5.
Hi again!
That is strange, those instructions should work on all our devices that are still being supported.
Make sure that you press the power button once so you see the menu for shutdown and restart on your screen, tap and hold on "Shut down" until you see a small new window > tap on OK.
Let know how that works out! 