Can't adjust the brightness level

[siwulskan]

Ever since I updated my software from Lollipop 5.1.1 to Marshmallow 6.0.1 just a few hours later the brighness level of the screen went to the lowest possible. Now the brightness adjustment just doesn't work, no matter what, the phone screen is at it's darkest and it's also slightly blinking. 

[Emir1]

Hi @siwulskan,

Have you activated the Adaptive brightness setting under Settings > Display > Adaptive brightness? I recommend turning it off and then adjusting the brightness level to see if it makes a difference. If you still experience the same behaviour, try rebooting your device in safe mode and try the same procedure again.