Update ui6

[Solera1]

After the update, my device does not lock the screen. It has a black screen. And the power button doesn't work. I've done everything. This update is truly rubbish. It was okay. The screen keeps flashing. It looks like it's burning.#ui6#update

[BandOfBrothers]

@Solera1  can you please try these generic troubleshooting steps. 

• 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 or use a Tv's USB Port 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. 
• Last resort is to backup and factory reset. 
• A Samsung Service Centre can assess your phone. 

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