Auto restart

[Huseynagha]

Hi , my phone automatically rebooted twice a week, the base version is one one ui5.1

[pete00]

Have you got the auto optimisation ticked ??

[Egg1]

You should consider yourself lucky it's only twice.
If you open members app after and it was an error, it gives you the option to send an error report, or does on mine.
This will make absolutely no difference to your problem and will be ignored by developers.
This is because they would like you to get sick of your device and buy the latest, which will of course be working much better until the next release 🤣
Or as said already, it could be this.

[BandOfBrothers]

Hi @Huseynagha 

Assuming you do not have the auto restart function activated can you perhaps consider the following troubleshooting generic guides.

• Make sure all your apps and phone's software is updated.
• Delete anything obtained via apk files.
• Safe Mode  > https://www.samsung.com/uk/support/mobile-devices/how-to-start-my-galaxy-device-in-safe-mode/ turns off downloaded apps and themes etc which may highlight an app or theme that's causing conflict. 
• Clear Cache Files from the phone's System Partition Section  > https://www.samsung.com/uk/support/mobile-devices/how-do-i-clear-the-cache-on-my-device/ You may need to insert your earphones or hook upto a powered On Laptop to access the Clear Partition Section. This may help with lag or stutters as this clears the phone of old/unused or broken cache files.There is also a Repair Apps option in the Menu System too. 
• As a very last resort back up and Factory Reset. When re setting up the phone however don't use the back up but instead set it up as a new phone and download your apps via your MyLibrary in your Playstore App just incase something in the back up is corrupted.
• A Samsung Service Centre can assess the phone.

If I can be of any further help then please don't hesitate. Take care.  😎 

[IиƑƩcTed_HȝʌЯͲ]

You are lucky , i have that auto restart function on and my phone never restarted in the last 2 months