Well, the problem is not only experienced by you but several other users have also come up with the same issue. However, after reviewing a lot on the issue, I have gathered some of the best solutions that can completely help you to get out of the problem.
Force reboot your device by simply pressing and holding Power + Home button until you get Maintenance boot mode. Then you have to select Normal boot and the problem can be solved.
Update the apps, which are not updated as the issue, can be due to not updated apps. So simply go to Google play store > Menu > My Apps and then go to “Installed” option where you can find whether the app needs update or not.
Reinsert the SIM card as many times due to improper SIM card, the problem can occur. So its better to remove the SIM card once and again reinsert it and check whether the problem is solved or not.
If possible then uninstall and again reinstall the app when you come to know the problem is because of the particular app.
Free up some space on your Samsung device. May be to less storage space, the error occurs. So try to delete the unwanted things on your device and make some space so that any error won’t exist any further.
You can get more solution on: Fix “Unfortunately, phone has stopped” error on my Samsung Galaxy S9