[Samsung Galaxy A50 Questions & Answers] Atharkhan101:
I HAD the same issue an I resolved it.

There are 2 methods to overcome this problem.

I even wrote a PDF and attached here in this post.

Below is SOME content from the PDF so it could be easy for users to find it on Google. I still strongly recommend you to refer to the PDF attached as it has pictures as well.

Samsung Galaxy M31 / Samsung M31 Screen is stuck on the following error message / error screen:

‘This phone’s bootloader is unlocked and the software integrity can’t be verified. Any data on this phone may be vulnerable to attackers. Don’t store any important or sensitive information on the phone.’

‘The phone is not running Samsung’s official software. You may have problems with features or security. And you won’t be able to install software updates.’ (error screen looks like below):

I was using correct TWRP and I was on Android 11 One UI 3.1.

Just to experiment, I flashed wrong TWRP version which was meant for Android 10 while being on Android 11. And so this problem started. Stuck on the error screen. Phone will not power off or on. Could not even enter the bootloader screen. Nothing works whatever keys I press. The same screen comes up. When the phone goes off and the phone will not accept charging that mean even you it whole night connected to charger, phone will not be charged- the same error screen.

So, the battery was not charging (my battery was at 24% just before this tragedy happened. It was late night and I thought of waking up tomorrow and plug in charger for an hour thinking if its battery is quite charged then I will follow Fix Method 2).

I woke up next morning and the phone was off (Battery drained fully). To this I was happy thinking that I can now hold Volume + and Power key and connect USB cable to enter Bootloader. When I did that phone would enter bootloader and gets switched off automatically (remember the battery was drained completely, charger too failed to charge battery and phone is not drawing enough power from USB port to stay on bootloader. On bootloader screen the phone’s display is fully on so more power usage).

Now I knew that the USB port is not proving enough power so that the phone could remain On while in bootloader when I hold Volume + and Power key and connect USB cable to enter Bootloader. I know for sure that Fix Method 2 will fix this for sure but it’s quite tiring.

So I referred to my PC manual to figure out which USB port provides maximum power. I found the right port (refer pic below):

So now I figured out 5 Volts port and plugged the original white Samsung M31 USB cable into one (refer the pic below):

If you don’t know which USB Port is 5 Volts then I recommend you to try all the ports and try getting to bootloader screen.

So when the phone was off, I pressed and hold the Volume up and Volume down key and with other hand I connected USB cable and now the phone went in bootloader and then I quickly flashed the right TWRP. Disconnected the USB cable and put the phone to charge and now it was accepting charge. Phone was back into life.

So I resolved it by Fix Method 1 below:

Fix Method 1: On my PC, I located the 5 Volts USB port and plugged the original white Samsung M31 USB cable into one (refer the pic below):

Entered Bootloader screen.

How to enter bootloader screen:

Assuming your phone is unlocked and the developers options are on and you have enabled USB debugging in Developer options and you have little knowledge of flashing firmware or TWRP via Odin.

Press and hold Volume Up and Volume down keys together with one hand and using other hand, connect USB cable to phone and release all the keys. Now phone will show bootloader screen which looks like below pic:

I quickly flashed the correct TWRP via Odin:

Flashing TWRP:

· Make sure OEM Unlock is ON in developer settings;

· Turn off the phone;

· Press the volume down + volume up button whilst the phone is connected to a pc to boot in download mode;;

· Long press vol up then confirm you want to unlock bootloader (this is needed one time only);

* Please be aware all your data will be erased including internal storage and phone will reboot!!

· Let the phone boot normally, pass the setup and connect to internet (wireless or mobile data) in order to unlock RMM;

· Make sure OEM Unlock is ON in developer settings;

· Turn off the phone;

· Use Vol up + Power + usb cable plugged to a pc to start the phone in download mode, short press vol up to confirm you want to go to download mode;

* If by any chance you see RMM state=Prenormal or KG state=Prenormal, factory reset data and redo from step 5!

TWRP screen was up. I tapped on Reboot and it did not reboot because the battery was not enough charged however I saw that TWRP Menu this means TWRP was working so the phone will boot up once it is charged.

Now I plugged in charger and was happy to see the correct charging screen (refer below pic):

I would turn power switch Off and On it quicky to know the charging percentage.

When it reached 20% I started phone (obviously by long pressing power key and it booted up just fine).

I loved myself :D

Fix Method 2:

Remove the phone’s back cover.

Be careful while removing the back case as you could screw the finger print sensor.

Disconnect the battery connector from motherboard and reconnect it.

Do not turn on the phone. As turning On will again get you back to the same error screen.

Put the back cover on.

Connect charger. Do not turn phone On yet. Wait for 5 min.

Do not even touch the phone.

Now you need to know the percentage of charge so do not hit the power button yet instead locate the main switch to which your charger is connected. Quickly turn Off and On and look at phone it shows charging percentage.

Once charging percentage reached around 20% you can touch your phone :D and power it on and it should boot up fine. It should not take more than 5 min to boot up.