Please regenerate your xorg.conf with >>sudo dpkg-reconfigure xserver-xorg<<. Confirm every question with enter. After this please add the line >>Option "ForceEnablePipeA" "true"<< to your xorg.conf device section and restart X. It should look like this?
Please regenerate your xorg.conf with >>sudo dpkg-reconfigure xserver-xorg<<. Confirm every question with enter. After this please add the line >>Option "ForceEnablePipeA" "true"<< to your xorg.conf device section and restart X. It should look like this?
Section "Device"
...
Option "ForceEnablePipeA" "true"
EndSection
If the issue still appears attach your current /var/log/Xorg.0.log and the output of dmesg and >>xrandr --verbose<<.